Merged pull requests 138, 139, and 140
 - Default to hidden visibility for Regal and statically linked library dependencies.
 - Update boost headers to 1.56.0 to get newer compiler support for Visual Studio 2013
 - Add Linux support for abi-dumper output for Regal and Regalw shared library targets.
Don't include <machine/cpu-features.h> as this was causing compile issues on Android.
Fix the paths of ES & EGL libraries to load on Android.
Bump 'export'ed version to 4.5 and regen all the files.

Initial version of script to convert khronos xml files into Regal's .py format.
See https://cvs.khronos.org/svn/repos/ogl/trunk/doc/registry/public/api
Includes a lot of reconciliation of Regal's gl.py and Khronos gl.xml.