glapi: Alias VertexAttribDivisor and VertexAttribDivisorARB.

There's no reason to have separate slots in the dispatch table for
these two functions, since they are synonymous.

Note: previous to this patch, we never populated the dispatch table
slot for VertexAttribDivisor, which was ok, since it is not required
until 3.3.  After this patch, both functions will be usable provided
that the ARB_instanced_arrays extension is present.
_mesa_create_exec_table: de-deprecate GetPointerv.

glGetPointerv was de-deprecated in GL 4.3, because GL 4.3 adds
functionality from KHR_debug and ARB_debug_output, which require
glGetPointerv.

This patch modifies _mesa_create_exec_table() to populate
glGetPointerv in the dispatch table for core contexts.

Technically this is not in compliance with the spec--what we really
ought to do for core contexts is expose glGetPointerv only when a GL
4.3 context is in use or one of the two extensions is present.
However, it seems silly to go to that extra work, since the only
client-visible effect would be for glGetPointerv to raise an
INVALID_OPERATION error instead of an INVALID_ENUM error.  Besides,
the other functions set up by _mesa_create_exec_table() only depend on
the API in use, not on the GL version or extensions supported.

Cc: Jordan Justen <jljusten@gmail.com>
_mesa_create_exec_table(): deprecate ProgramStringARB.

This function is only useful for the ARB_{vertex,fragment}_program
extensions, which we don't expose in core contexts.
_mesa_create_exec_table: GLES3 fixes.

This patch sets up the dispatch table for the following GLES3
functions when a GLES3 context is in use:

- BeginQuery
- BeginTransformFeedback
- BindSampler
- BindTransformFeedback
- BlitFramebuffer
- ClearBufferfi
- ClearBufferfv
- ClearBufferiv
- ClearBufferuiv
- ClientWaitSync
- CopyBufferSubData
- DeleteQueries
- DeleteSamplers
- DeleteSync
- DeleteTransformFeedbacks
- EndQuery
- EndTransformFeedback
- FenceSync
- FramebufferTextureLayer
- GenQueries
- GenSamplers
- GenTransformFeedbacks
- GetInteger64v
- GetQueryObjectuiv
- GetQueryiv
- GetSamplerParameterfv
- GetSamplerParameteriv
- GetStringi
- GetSynciv
- GetTransformFeedbackVarying
- GetVertexAttribIiv
- GetVertexAttribIuiv
- IsQuery
- IsSampler
- IsSync
- IsTransformFeedback
- PauseTransformFeedback
- RenderbufferStorageMultisample
- ResumeTransformFeedback
- SamplerParameterf
- SamplerParameterfv
- SamplerParameteri
- SamplerParameteriv
- TransformFeedbackVaryings
- VertexAttribIPointer
- WaitSync

And it avoids setting up the dispatch table for these non-GLES3
functions:

- ColorMaski
- GetBooleani_v
- Enablei
- Disablei
- IsEnabledi
- ClearColorIiEXT
- ClearColorIuiEXT
- TextureStorage2DEXT
- TextureStorage3DEXT

Cc: Matt Turner <mattst88@gmail.com>
_mesa_create_exec_table: GLES1 fixes.  TODO: more.

Currently, _mesa_create_exec_table() (in api_exec.c) is used for all
APIs except GLES1.  In GLES1, _mesa_create_exec_table_es1() (a code
generated function) is used instead.

In principle, this shouldn't be necessary.  It should be possible for
api_exec.c to contain the logic for populating the dispatch table for
all API's.

This patch paves the way for using _mesa_create_exec_table() instead
of _mesa_create_exec_table_es1(), by making _mesa_create_exec_table()
(and the functions it calls) expose the correct subset of desktop GL
functions for GLES1.

Unfortunately, we can't switch over to _mesa_create_exec_table() quite
yet.
WIP: mark stuff as deprecated
WIP: mark more stuff as deprecated
WIP: mark more stuff as deprecated
Whoops, erroneously marked DrawBuffer as deprecated
Whoops, StencilFuncSeparateATI should be deprecated, not StencilFuncSeparate.
Whoops, PolygonOffsetEXT should be deprecated, not PolygonOffset
Never mind, GetPointerv shouldn't be deprecated.
glapi: use GL_ or GLX_ prefix for all category names.

This patch standardizes the category names used in the glapi XML files
to begin each extension name with the prefix "GL_" or "GLX_".  There
is no functional change, because these category names are not used in
the generated code.
Deprecate TexBumpParameter{if}vATI, since we already depreacte the other functions in ATI_envmap_bumpmap (and the extension itself)
Whoops, I think StencilFuncSeparateATI should not be deprecated
Oops, ProgramStringARB should be deprecated
HACK: remove #if 0 blocks from api_exec.c
HACK: remove comments from api_exec.c
HACK: remove blank lines from api_exec.c
HACK: manually inline functions