* 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!