Revert SHA1 additions.

The shader-cache isn't finished, so the configure checks are a bit
premature and will only stand to confuse users of Mesa 11.0.

This is a squash of the follow four reverts:

   Revert "Rename sha1.c and sha1.h to mesa-sha1.c and mesa-sha1.h"
   Revert "configure: Add machinery for --enable-shader-cache (and --disable-shader-cache)"
   Revert "sha1: Fix gcry_md_hd_t typo."
   Revert "mesa: Add mesa SHA-1 functions"

Reviewed-by: Carl Worth <cworth@cworth.org>
6 files changed