Move plot into MPLFitter; support style args; improve docstrings.
Cleanups import and unused variables, fix typo.
Merge pull request #2 from tritemio/fitter-plotting

Cleanups import and unused variables, fix typo (min -> max).
Merge pull request #124 from danielballan/fitter-plotting

Move plot into MPLFitter; support style args; improve docstrings.
correction in model.__add__ method, so we can deal with the case single_model + composite_model
FIX: Detects scalar indep vars properly; also accept Python lists.
FIX: Broadcast a constant result in model.eval()
Merge pull request #125 from licode/model_sum

correction in model.__add__ method
allow IPython version < 2 to not try to load widgets
cleaned up flow in Model.__add__()
updated Thanks file
Merge pull request #126 from danielballan/scalars-and-list

Scalars and list
Merge pull request #128 from newville/master

Cleanup of Model.__add__() + two bug fixes
Add tests for composite models __add__
Merge pull request #129 from tritemio/comp_models_add_tests

Add tests for composite models __add__