* Remove difflib's quick_ratio() call, from quick tests looks it is four times slower than ratio(), and yet it gives the same results...
* Moved code to find all po's in a dir into its own func (will be used by i18n addon tools too).
Also workaround a nasty bug, where unregistered py classes remain listed in relevant __subclasses__() calls, which would lead to crash with python addons i18n tools (main translation was not affected, as messages extracting tools are executed in a brand new "factory startup" Blender ;) ).
We have a glicth with colormanagement's spaces descriptions, though, looks like they are clamped at 64 chars (see raw space), will see that later, if it’s solvable.
Fix for keyingsets tips, and make them (and a few others) findable by i18n messages extracting code (for some reasons, their bl_rna.description are void???).
Most notable difference from now on will be that all py is handled from current blender's resource dirs, no more from source dir. Better for consistency, and avoid e.g. cycles' addon to be checked twice...
Notes:
* Everything is still a bit raw and sometimes hackish.
* Not every feature implemented yet.
* A bunch of cleanup is still needed.
* Doc needs to be updated too!
Also enhanced the ugly py ast parsing code, so that it now can handle (up to some extent) "name" function nodes, and add bpy.app.translations.pgettext func familly to extracted ones...
This ast py parsing becomes more and more ugly, should probably try to refactor it a bit. :/
Also generate rigid body constraint types in py bullet code from RNA enum values (simpler than having to sync the code when something is changed here!).
Side note: RNA API about icons still needs to expose icons for enum values, and conversion funcs between icon_name and icon_value!
* handle nicely multiple empty lines in po files (still have to figure out why po writer sometime output two lines instead of one!)
* fix rtl processing!
Notes:
* Most tools here have been updated, only a few (unused :p ) features should be missing. But some updates are rough for now, and performances are globally worse currently, will address this later (this is only really noticeable when you work over the whole repo, anyway ;) ).
* This update breaks "edit translations" addon, will fix it later, once core (i.e. this module) is considered stable again!
