gltrace: Add support for NV_framebuffer_blit.
glretrace: Destroy Context only once via glXDestroyContext

Handling adapted from retrace_wglDeleteContext
qapitrace: ignore supporting files generated by qtcreator

When using qtcreator for build/debug, qtcreator creates miscellaneous
helper files that don't need to be seen by git.

Signed-off-by: Lawrence L Love <lawrencex.l.love@intel.com>
Update GL/glext.h which has a modified argument list for glClearNamedBufferSubDataEXT.
glws_waffle: Support shared contexts.
glretrace: Default to PROFILE_ES2 for EGL.

It should the most common profile for EGL.

Suggested Chad Versace, was quick workaround for issue #197.
md5: Add MD5 library.

From http://www.fourmilab.ch/md5/ .
glretrace: Add '--snapshot-format=MD5' option that allows write image MD5 to a text format file.

Collecting MD5 is obtained based on raw buffer.  Rendering results are
reproducd accurately.  Creating .txt in place of PNG Format, that would
save more disk space and run faster.

Reference command:

    glretrace  --snapshot-format=MD5  -s /tmp/MD5.log  smokinguns.trace
md5: Fix gcc warning.
retrace: Document MD5 snapshot format.
retrace: Make --snapshot-format=MD5 work as documented.

--snapshot-format is the standard output format. -s is the prefix, not
the actual filename.

That is, for MD5 one should do:

  ./glretrace --snapshot-format=MD5 -s - app.trace
image: Fix bug in RAW image output.
image: Simplify MD5 calculation and output.

No intermediate buffer.
image: Avoid snprintf.

Fixes MSVC build failure, as MSVC only defined _snprintf.
qapitrace: ignore more supporting files generated by qtcreator

Missed this extension the previous commit:
"qapitrace: ignore supporting files generated by qtcreator"

Note: *.moc_parameters files are generated by cmake.  Without
them, the following make error occurs:

moc: Cannot open options file specified with @
...
make[2]: *** [gui/apitrace.moc] Error 1

Signed-off-by: Lawrence L Love <lawrencex.l.love@intel.com>
glretrace: Replay failing wglMakeCurrent calls correctly.

If wglMakeCurrent failed in the trace, then just make current NULL.
glretrace: Prevent deadlock on SetWindowPos.

Achieve this by using a dedicated thread to process window events.  It is
the only practical solution for this.
d3dretrace: Assert SetWindowPos is called on the window thread.
glretrace: Enable all debug output.

On nVidia systems, not all debug output is enabled by default. If we wish to
have the driver tell us where it is placing buffer objects, for example, we have
to enable all the debug channels by passing GL_DONT_CARE to everything in
glDebugMessageControlARB(...)
glretrace: Limit the low severity messages.

Otherwise some traces will be full of them...