Improve validation by also checking internal types.
Improve symbolic typing for aliphatic carbons.
Update tests to run on command line.
Aromatics still need some work but the carbon types look okay.
Reorder definitions so aliphatic nitrogens are tested first
Confirm aliphatic nitrogen definitions, some problems due to aromaticity but otherwise okay.
Small modification fo NPO2 etc.
Phosphorus types confirmed (required a special case)
Spacing
Clean up sulfur patterns
Cleaner oxygen definitions
Two stage atom typing allows complete recall of internal MMFF atom types.