Add LICENSE line to some .py files in astropy.models
Fix warning statements
Fix parameter name in NonLinearLSQFitter.__call__
Fix some issues (mostly cleanup) in models

There are things that were pointed out by Eclipse PyDev code analysis
Rename astropy.util to astropy.utils

This is more consistent with other packages I believe.
Rename test_pars.py to test_parameters.py

To be consistent with the module name parameters.py.
Merge pull request #1 from cdeil/model3

Some updates to astropy.model