Add a timer for FS Preprocessor

Tracks time spent in FS PP, reports that time, and reports stats with that time excluded.
Add vogl_analysis.py script and enhance FS PP to enable NULL FS substitution

Vogl_analysis.py provided to do frame analysis.  See details in comment at top of vogl_analysi.py file.

Added FS PP Null capability to selectively modify FS to output constant color.
Added "--fs_preprocessor_prefix <path>/prefix" option to dump all in/out shaders to/from FS PP to specified location w/ given prefix.
Merge pull request #154 from tobin-lunarg/fs_pp_timer

Add a timing stats for FS Preprocessor
Merge pull request #155 from tobin-lunarg/null_shader

Null shader and Frame Analysis capability
Add missing GL api calls for Source2 on Windows
Merge pull request #156 from tobin-lunarg/source2_support

Add missing GL api calls for Source2 on Windows
Fixes for SSO state snapshotting
Merge pull request #157 from tobin-lunarg/source2_support

Fixes for SSO state snapshotting
Allow SAMPLE_BINDING snapshot if ARB_sampler_objects extension supported

This fixes a trimming bug on Intel MESA. SAMPLE_BINDING was not being captured b/c Mesa currently only GL 3.0 and SAMPLE_BINDING is 3.3.  However, Intel MESA supports ARB_sampler_objects extension so with this change it will now capture SAMPLE_BINDING state.
Merge pull request #158 from tobin-lunarg/intc_trim_fix

Allow SAMPLE_BINDING snapshot if ARB_sampler_objects extension supported
Remove vogleditor.ui.autosave file introduced in 2ed4a9b

(kept thinking this was a locally introduced file I was generating)
Merge pull request #159 from lawlove/master

Remove vogleditor.ui.autosave file introduced in 2ed4a9b
SSO snapshot and restore improvements

Restore SSO when input handle is zero and track GL_PROGRAM_SEPARABLE state for program objects.
Merge pull request #160 from tobin-lunarg/sso_support

SSO snapshot and restore improvements