mesa: Remove support for GL_MESA_texture_array

mesa: Remove support for GL_MESA_texture_array

This extension enabled the use of texture array with fixed-function and
assembly fragment shaders.  No applications are known to use this
extension.

NOTE: This patch regresses GL_TEXTURE_1D_ARRAY and GL_TEXTURE_2D_ARRAY
cases of the copyteximage piglit test.  The test is incorrectly using
texture arrays with fixed function while only requiring the
GL_EXT_texture_array extension.  A fix for the test has been posted to
the piglit mailing list.

http://lists.freedesktop.org/archives/piglit/2013-November/008639.html

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>