Added parsing of ionic part of lepsilon in Outcar. Changed parsing of piezoelectric tensor unit from e.Angstrom to C/m^2. Fixed results' data structure from numpy array to list.
Added test files for testing parsing of lepsilon from OUTCAR
Added test functions for testing parsing of lepsilon from OUTCAR
changed comments
Merge pull request #174 from petousis/master

Fixed lepsilon parsing from OUTCAR