(requested by al)

manifest

Subclass detection didn't include the class itself if all it's subclasses
were invalid. As we create a new regrouping subclass, that was always the
case after a registry reloading, causing subclassed controllers to not be
taken in account.

[IMP] routing_map: clean code a little bit

[FIX] read_group: do not change the return format of the read group in case of no groupby_fields and keep the same return format as with groupby fields (a list of dict)

Instead of only taking direct subclasses of controllers, take the lowest controller in the hierarchy
Allowing subclassing controllers

[FIX] logging PostgreSQLHandler: expand message + use contextmanagers to handle exceptions and cursor

Before this commit, @mode=primary would be sorta-ignored[0] if the current
view and its parent had the same model: the current view would *still* get
applied (as an extension) when asking OpenERP for its parent. This commit
makes mode=primary views behave regularly, they are *never* applied when
asking for their parent, only when asking for them or their children.

This allows "forking" views, and using extended views in some contexts without
breaking or duplicating the original view

[0] there was actually a problem when asking for the current view directly,
    first its parent would be resolved by applying it, then it would be
    applied to resolve itself, the view would thus get applied twice (oops)