Blender Git Loki

2.5: ID datablock button back, previously known as std_libbuttons. The
way this worked in 2.4x wasn't really clean, with events going all over
the place and using dubious variables such as G.but->lockpoin or
G.sima->menunr. It works as follows now, for example:

xco= uiDefIDPoinButs(block, CTX_data_main(C), NULL, (ID**)&sima->image, ID_IM, &sima->pin, xco, yco,
sima_idpoin_handle, UI_ID_BROWSE|UI_ID_RENAME|UI_ID_ADD_NEW|UI_ID_OPEN|UI_ID_DELETE|UI_ID_ALONE|UI_ID_PIN);

The last two parameters are a callback function, and a list of events
or functionalities that are supported. The callback function will then
get the ID pointer + event to handle.