add regtest for subspace diagonalization plus fix bugs

git-svn-id: svn://svn.code.sf.net/p/cp2k/code/trunk@14809 bac0169d-1eea-4375-b5f6-f89d2ced9994
Dashboard: Update convention check

git-svn-id: svn://svn.code.sf.net/p/cp2k/code/trunk@14810 bac0169d-1eea-4375-b5f6-f89d2ced9994