Require CMake >= 2.8.7 so we can use CMAKE_GNUtoMS

git-svn-id: https://icl.cs.utk.edu/svn/lapack-dev/lapack/trunk@1465 8a072113-8704-0410-8d35-dd094bca7971
Remove GNUtoMS code in favor of CMake builtin version - Thanks Brad (Kitware)

git-svn-id: https://icl.cs.utk.edu/svn/lapack-dev/lapack/trunk@1466 8a072113-8704-0410-8d35-dd094bca7971