update gitignore file
Add reseltable.py file.  Copied from Assembla.com.  Needed to support reselcat.  This has no impact at this time.  Additional modifications need to be made to observationmode.py, obsbandpass.py, and observation.py to implement support.
Remove class imports for __init__.py.  Circular import cleanup work.
Change call to BlackBody to reflect new API.  Circular import cleanup work.
Merge pull request #21 from chanley/master

circular import work