Consolidate the MD5 sums into one location and add a --without-turbojpeg switch to...

Consolidate the MD5 sums into one location and add a --without-turbojpeg switch to the Un*x build to allow building libjpeg-turbo without the TurboJPEG/OSS wrapper library.  These modifications were supposed to lay the ground work for adding compile-time-selectable 12-bit JPEG support, but unfortunately there are deeper issues that prevent the implementation of that feature right now (namely, some of the modifications made to the C code to support the SIMD code are apparently not 12-bit-friendly.)

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@902 632fc199-4ca6-4c93-a231-07263d6284db