CryptoMiniSat2 is using the same MTL and MTRand directory as that of

CryptoMiniSat2 is using the same MTL and MTRand directory as that of
CryptoMiniSat1. This is made explicit by the Makefile's -I directives.
Therefore, there is no need to have it twice in the source tree. Also,
some files in CryptoMiniSat2 have been changed to have 'mtl/' in front
of their #include directives. This was superflous, as the Makefile
already -I includes the ../cryptominisat/mtl and ../cryptominisat/MTRand
directories in the search path.Effectively, with 'mtl' directory in,
and the #include 'mtl/X.h', it was compiler-implementation specific
which file was included (either cryptominisat/mtl/X.h or
cryptominisat2/mtl/X.h), therefore potentially making debugging next to
impossible and the build fragile in the future (if ever the two mtl
directories will be different)

git-svn-id: https://stp-fast-prover.svn.sourceforge.net/svnroot/stp-fast-prover/trunk/stp@439 e59a4935-1847-0410-ae03-e826735625c1