Fix is a bit ugly, but cannot think of another solution for now, at
least this **should** not break anything else.
And now I go find myself a very remote, high and lonely mountain, climb
to its top, roar "I hate proxies!" a few times, and relax hearing the echos...
Issue here was that py API code was keeping references (pointers) to the
liniked data-blocks, which can actually be duplicated and then deleted
during the 'make local' process...
Would have like to find a better way than passing optional GHash to get
the oldid->newid mapping, but could not think of a better idea.
This commit adds operators and Outliner menu entries to reload or relocate a library,
and to delete or replace a datablock.
RNA ID API is also extended to allow ID deletion and remapping from python.
Review task: D2027 (https://developer.blender.org/D2027).
Reviewed by campbellbarton, thanks a bunch.
Previous to 2.77, this used to be default behavior, was changed in rB591f4549c958b.
However, in most append cases, you do want a full localization of your data, so this new behavior
is kept by default, but there is now an option in append operator to only localize the 'first level'
of data (i.e. datablocks from linked library itself, and not those from other 'sub-libraries').
This commit adds a new `wm_files_link.c` which contains everything related to append/link code,
moved from `wm_operators.c` (rather small currently, but will expand quite a bit with future reload & asset works).
It also moves all load/save .bland files (and related userpref/startup stuff) from `wm_operators.c`
to `wm_files.c` (some helper funcs were already there).
This also makes `wm_operators.c` significantly lighter.
