Use python 3.5
Refer to correct page of the doc
Remove old bazar to git (was intended for the 8.0)

Remove outdated setup_dev script: it was intended for odoo developers but if you
are not able to make a git clone, you are going to have a bad time later.

In the beginning Odoo Enterprise addons contained a second web module. At some
point that was replaced with web_enterprise, but the documentation wasn't
updated.

Describe the proper changes.

Closes #16302

Before this revision, the installation instructions where
Community-centric, which led some customers to believe
that they had to install first Community then Enterprise.

This commit makes the instruction compatible for both editions.