Adds basic DALTON mol-file writer
Adds DALTON mol-file reader

  * adds a more sensible choice for the default
    basis set.

  * removes superfluous line break in the writer
Adds option to write atomic units

  * Clarifies some error messages
Adds basic DALTON log file reader

  * it can read atoms from a log file
Cannot read INTGRL format in DALTON.
Do not attempt to read Z-Matrix input.
Merge pull request #8 from cstein/master

Basic Dalton .mol file generator