Deprecates the previous pkg_resources-style packages. Our use was
not entirely spec compliant, and it broke with setuptools 31.
More information in https://github.com/odoo/odoo/pull/15718

Instead, use the pkgutil-style namespace packages.
This is spec compliant as long as all other distributions providing
odoo.addons use PEP 420 namespace packages (i.e. no __init__.py).
So this mechanism fully works on Python 3 only, but does not break
anything on Python 2.

See also:
https://packaging.python.org/guides/packaging-namespace-packages/#pkgutil-style-namespace-packages

Closes #19517
Fixes #15718

On UNIX, the timezone modules conversions can be reset by using
`time.tzset()`. On windows this is not available and the timezone (TZ)
environment variable must be set before the first import of time module.

If not, all datetime gotten in python without specifying UTC (such as
datetime.datetime.now) could be wrong.

This was fixed with 4a77c6a0 in 2013, but has come back since 389c2ba9
imported pkg_resources (which do  a `time` module import) before that.

closes #14926
opw-693764

by auto-extending addons path with odoo.addons.__path__.

This patch also introduce
  * an explicit declaration of odoo.addons as a namespace package
    This is necessary because the standard way of declaring namespace
    packages in setup.py does not work as long as odoo/__init__.py
    contains code.
  * a more reliable way to find odoo root path.

The use of an entry point was considered in order to provide
an `odoo` command in the path for the packages users, but the
generated entry point will first check that all the things in
install_requires were provided in a not bright way: it'll check
that it matches a distribution name. This does not work because
python-chart does not have the distrubtion name "pychart" which
is provided by the python-pychart package in debian jessie. Same
for suds-jurko which is provided by python-suds in debian stretch
but does not have the distribution name "suds".

Also, adapted the  packages tests to these cli changes.

bzr revid: al@openerp.com-20121127005513-vi9viu4oafbrze6y

bzr revid: chs@openerp.com-20121123105120-m1h2uiwk8baa8kin

bzr revid: nicolas.vanhoren@openerp.com-20121122145309-bim6m10p0q7rf6wj

bzr revid: odo@openerp.com-20121029173321-clq0p2z2dh3ld8mu

bzr revid: al@openerp.com-20120922124354-unk1u8a9anst5hwo

bzr revid: al@openerp.com-20120922111714-moxkguy729vout9x

bzr revid: al@openerp.com-20120922105107-q02ogtsfudphzkl6

bzr revid: chs@openerp.com-20120911115003-8a9a0f8dsoirkx9i

bzr revid: chs@openerp.com-20120907144102-qi35brwee3wh9fwb

bzr revid: stw@openerp.com-20120904073502-xce3wn064f8e0pru

bzr revid: vmt@openerp.com-20120903145929-p4kp6eotkcflletk

bzr revid: chs@openerp.com-20120822101156-v5w2kljumas2cyq0

bzr revid: vmt@openerp.com-20120329132028-3cjq7mt0yqbk2g00

- The previous implementation was optimized to make few queries to the database
  but needed to keep some internal state.
- That state was updated whenever the ir_cron table was modified by the ORM
  (this works only when the cron and web processes/threads are inside a single
  OpenERP server instance).
- The new implementation is instead polling the database.
- This is deemed acceptable in `normal` situation (i.e. not a SaaS with
  thousand of databases).
- This makes it possible to avoid sharing state or the use of IPC.
- This makes it possible to add/remove additional worker processes,
  possibly on different machines.
- The code of the older implementation is removed in this commit but
  will be added back in a later commit: this is the 6.1 stable branch
  and we don't want to change the existing installation, but simply
  provide a solution for those running OpenERP with Gunicorn (which
  uses processes for which no cron state were shared).

bzr revid: vmt@openerp.com-20120328090320-vshsfv3gt1ck34s1

bzr revid: odo@openerp.com-20120316111218-o963t7xm4r4honoy

Report-printing threads don't seem to be included
in the list of active threads, but do need to
be dumped as well.

bzr revid: odo@openerp.com-20120315181355-phtkn2uhy638ei1e

lp bug: https://launchpad.net/bugs/917565 fixed

bzr revid: stw@openerp.com-20120214114447-f8k2ze9kszfxvlw1

lp bug: https://launchpad.net/bugs/929466 fixed

bzr revid: vmt@openerp.com-20120209152732-24ud1f70krliv2k5

bzr revid: vmt@openerp.com-20120209141444-12261k6zd2ovnltd

bzr revid: vmt@openerp.com-20120202173522-2grq11zfm7855i6s

use the openerp.addons namespace), and correctly set the submodules in
sys.modules (instead of only the top-level package).

bzr revid: vmt@openerp.com-20120201152710-s7sxlgibwd3lwr5l

bzr revid: florent.xicluna@gmail.com-20120201123311-yvljvcj0luly77qt

bzr revid: vmt@openerp.com-20120124105333-moq92a20za31m132

Calling this method is no longer required since the
merge of the new code for loading translations using
a temporary table. The method itself has been removed
at revision 3919, so all calls to it should have been
cleaned up as well.
Rev.3919 = rco@openerp.com-20111223104824-fup1cjbjni1fsty1

bzr revid: odo@openerp.com-20120109140958-10i1ti16tw327580

bzr revid: vmt@openerp.com-20120109125243-qhtr070dvtc3akb5

openerp.modules as the namespace of the OpenERP addons.

bzr revid: vmt@openerp.com-20120109124120-06gguu3lzxv49i3j

(openerp.modules will be changed in openerp.addons in the next commit).

bzr revid: vmt@openerp.com-20120109123123-jt3canjbg0ozs05j

`import openerp.modules.<module_name>`.

bzr revid: vmt@openerp.com-20120109101647-4hvy3n6eifzeozzq

bzr revid: vmt@openerp.com-20120109090333-8ptsvj3yokjd59rm

bzr revid: vmt@openerp.com-20120109081206-p10yack8lhip11gt

this should be now fixed by making sure that --withou-demo flag (or its absence)
is taken care of, and setting the base module demo field.
Normally the demo state of a module should have a ripple
effect on all modules depending on it. This might prove
not enough in this case and require some more testing.

bzr revid: vmt@openerp.com-20111117162824-yqswv6yk7bmiyj4s

- update_module was defined as config[init] or config[update]
- this means it is a mutable dictionary
- the code testing update_module is actually mutating
config[init] and config[update]...
- now update_module is really a True or False value.

bzr revid: vmt@openerp.com-20111117100608-0n8o99slgk42kiiv

bzr revid: vmt@openerp.com-20111115163843-djq6hybp24lk9f5e