python

(excuse me for doing all in a single commit, but they are tiny
fixes and it's bpython, that dark corner ...)

#1025 - FileSelector SEGV on dynamic callback Category:

  Can't reproduce with current cvs, I'd say recent changes to fix
another crash related to FileSelector in gui-less scripts solved this
one, too.

#1028 - Reserved button event number:

  Menu choices generate two events, one extra related to the menu
itself, with value=4.  Made bpython ignore this extra event.

#1068 - FileSelector No file extension support:

  As Ton wrote there, Blender itself doesn't support this yet.  But the
requester also wanted Window.File/ImageSelector to accept a pathname.  Done.  Also updated doc.

#959 - Segfault on background rendering:

  This happened in bg mode (blender -b filename -a, for example) when
a script with the line "Blender.Redraw()" was linked to FRAMECHANGED events.  As reported in the bug page, it was because curarea is NULL in bg mode.  Made Redraw() check for this and not call functions that expected curarea in Redraw, like one to swap buffers.

#1072 - Blender.Redraw() Segfault:

  Good catch : ). Scripts called from the scripts win that called
Blender.Redraw() or Blender.Window.Redraw() would crash Blender because of a dirty pointer in Spacescript->script.  Fixed.