Blender Git Loki

RNA ui API: fix long-standing annoying glitches when using 'text' property of UI functions:
* No context-aware at all.
* Always translated (when i18n was enabled).

Now, it will try tu use RNA struct/property context if available, unless you specify a context within optional "text_ctxt" parameter.

And you can prevent translation by setting 'translate' parameter to False (is True by default).

Will clean up code in a later commit (remove PROP_STRING_PY_TRANSLATE flag and related code), and also fix uilist templates to translate no more materials/textures/etc. names!