configure.ac: add the --disable-strict-gles configure option
configure.ac: add the --disable-strict-gles configure option

The strict GLES wrapper checking each GLES calls with glGetError()
remains enabled by default. It can now be easily disabled at build time.
This program has so few GLES calls in the rendering loop that removing
glGetError() should not make any noticeable performance difference.

Signed-off-by: Julien Olivain <e017b3aecfdd2dc1bdcf241eeb088a15ff1e3ada@free.fr>

jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player