* Fix header menu spacing bug, and make it consistent for all headers.
* For consistency, always put menus first in the header, then any enums
to switch the type of data displayed.
* Node editor header ported to python layout. Still quite a few
operators missing to make the menus complete.
* RNA wrapped node editor, and added use_nodes property to material
and scene.
Image Window
* Unpack operator now works.
* Some small layout code tweaks.
Info Window Header
* Moved to python UI code.
* template_running_jobs, template_operator_search added.
* Ported external data operators: pack/unpack all, make
paths relative/absolute, find/report missing files.
Also
* Report RPT_INFO too, not only warnings and errors.
* Run UI handle functions after RNA and Operators.
* Rename particle system add/remove operators, to not
include "slot", that's only there for materials because
that's what they are called now in RNA.
