Revision numbering and cross platform fixes

* Added revision numbering due git commits
* Cpack package naming changed to include version and revision
* elmerf90.bat.in.cmake and elmerld.bat.in.cmake fixed to imitate
  elmerf90.in.cmake and elmerld.in.cmake
* tests link against the elmersolver library so that compilation
  does not fail in windows/osx due to error in compilation of tests
* added variable to bypass cpacking