Updated to work with Blender 2.59


[[Split portion of a mixed commit.]]

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

commented out line 784 #    bpy.types.DATA_PT_texface.append(_add_tface_buttons)

please test scripts in the ui before committing changes.

rectangular area lights had wrong coordinates (probably achievable with proper matrix but swapping and negating axis seems ok for now)

Plus a few styling enhancements.

[[Split portion of a mixed commit.]]

* Volume calculation and mainfold check code by Benjamin Lauritzen (Loonsbury)
* Updated API revision

Fixed a type error for dimensions of rectangular area lights 

Temporary mainfile used to be saved to current working directory
which isn't always available for writting.
Save temporary mainfile to temporary directory.

* Measurement of face normals by TNae + extended to cover all cases.
* Patch link: http://blenderartists.org/forum/showthread.php?177800-Measure-script-%28Blender-2.5x-only%29&p=1896219&viewfull=1#post1896219
* Grouped measured values inside boxes.

It was broken since 2.58a and problem was caused by sysconfig
module which tried to parse python configuration header (pyconfig.h).

Use dirname(platform.__file__) to determine libpath for python.