This is the py addon to use for embeded Blender ui translation. It can edit various UI elements' messages and tips, save the changes to the relevant po, "compile" a new mo placed into user's datafiles dir, and erase that same files (to get back "official" translations).

Notes:
* Still work in progress. Most likely some remaning bugs (even though it works quite well for me)...
* All UI elements in Blender aren't translatable this way (e.g. panel labels just don't react to right mouse clicks currently...)
* RTL languages won't work as well as others, still have to implement some kind of revert-RTL process...
* Having a nicer way than editing user_settings.py in modules/bl_i18n_utils to set up needed parameters is mandatory! Will try to use some kind of user preferences in user's config dir.

And a whole doc to write! :/