Removed one additional reference to bpy.app.revision. I don't see errors caused by this variable because it is defined in all windows builds I have access to.

MHX importer: automatic helper deletion is temporarily turned off, because it often made Blender crash.

MHX importer: Added new convenient FK/IK buttons, which both change the IK property and layer visibility.

MHX importer: Multiple UV maps now work correctly with Bmesh. Added FK-IK snapping, stolen from Rigify.

MHX importer updated for BMesh. There are still problems with multiple UV maps, but am unsure whether this is my fault.

MHX importer: temporary commit for Bmesh. UV coordinates are ignored, but at least the script does not crash.

MHX importer: vertex groups can no be loaded in chunks. Also changed definition of helper geometry, to faces with material >= 4. This allows helpers to have different colors in the viewport.

Mhx importer: added icons for pin buttons. changed disable layers so the first layer on with the active posebone remains.

Plus a few styling enhancements.

[[Split portion of a mixed commit.]]

Forgot to modify this files in recent commit.

Adding UNDO flag to import operators. Made this only for trunk addons.

* You only have to do layout.prop if you want 1 property, no need for row then!
* Use col, row, sub as variable names, not colsub, rowsub, row2 etc please.
* Povray Addon: Still used a lot of splits, you need no split when you only have 1 column!