Implementation Note:
* Moved the scene copy/unlink code back into blenkernel, with
the exception of the copy single user stuff which is still in
object_edit.c.
* Uses SCREENDELETE notifier like SCREENBROWSE, seems only clean
way to do this now.
DONE:
* moved almost all declarations from BLI_blenlib.h into their own proper header files.
* BLI_blenlib.h still includes all the declarations for convenience and to avoid changes in existing code
* split util.c into several files, where it wasn't done already
* DynamicList -> dynamiclist,
* ListBase -> listbase,
* String utility functions -> string.c
* removed a few unused macros and functions, if they're needed back, they're still in svn ;)
TODO:
* btempdir global
* further cleanup in the code of the different modules (especially util.c)
