Stage two of the giant animation recode project; Ipo/Action/NLA cleanup

-> Note; added 2 new c files (split editipo.c). MSVC needs upgrade.

Impatient people can check the goodies in CMS:
http://www.blender3d.org/cms/Action_and_NLA_editor.706.0.html

Most work was on trying to unwind the spaghetti for editing ipos. Too much
history and bad design got added here. Most evident changes:
- made generic 'context' for detecting which Ipo is being edited, or to
  assign ipos or to retrieve ipo curves.
- made generic insertkey() for all ipo types, including actions
- shuffled a lot of code around to make things more logical. Also made
  sure local functions are not exported

It is far from ready... when action/nla was added in Blender, a lot of
duplicate code was generated. That's for another time.

Now the goodies;
- made Actions to allow any Ipo type
- made NLA to define active actions, for Action window too
- corrected timing for active action, so it shows the 'real time', as
  defined in NLA editor.

I did update python code, but that would require testing. Testing is
needed for this commit in general, too many changes happened on all
levels of the animation system. :)
Will keep track of all reports this evening, hopefully it doesnt break
the pre-release schedule!

source/blender/src/SConscript

@@ -23,7 +23,7 @@ source_files = ['B.blend.c',
                 'cmovie.tga.c',
                 'cursors.c',
                 'drawaction.c',
-		        'drawarmature.c',
+		'drawarmature.c',
                 'drawdeps.c',
                 'drawimage.c',
                 'drawimasel.c',
@@ -50,6 +50,8 @@ source_files = ['B.blend.c',
                 'editgroup.c',
                 'editimasel.c',
                 'editipo.c',
+                'editipo_lib.c',
+                'editipo_mods.c',
                 'editkey.c',
                 'editlattice.c',
                 'editmball.c',