Molfiles

- Some more minor fixes to testing
- Laid the foundation for mol file parsing
molfile v2000

Started working on the (older) molfile format
MolV2000 object

- Added functionality to parsing molfiles (v2000) (maybe 70% done?)
- Stuck more closely to the abstraction in runtests (use vars not
__dict__, I should change everything that uses __dict__)
- Improved how main is called
- MolV2000Parser is implemented as a wrapper on MolV2000
- Tests for MolV2000 objects
more molv2000

- reorganized test directory molecules
- fixed unit tests accordingly
- expanded molv2000 capabilities