Atomic Properties calculations: new functionality
- Pressure tensor for Ewald/PME/SPME in Fist
- Pressure tensor for DFTB 
- Energy and Pressure tensor for DFTB3
- Use same symmetrization for total and atomic stress
- Add PRESSURE to 4 regtest, add 3 new regtests


git-svn-id: svn://svn.code.sf.net/p/cp2k/code/trunk@14775 bac0169d-1eea-4375-b5f6-f89d2ced9994