Begins implementation of Lafferty and Wyatt flux point method and API changes to flux_point.py

Adds xfail test command to added unit test
Add GaussianBand2D model
Add GaussianBand2D to docs
Improves flux_point API, adds lafferty method and unit tests and adds tutorial example
Makes some changes to the flux point tutorial to correct errors and improve clarity
Merge pull request #128 from ellisowen/flux_point_method

Flux point method
Fix broken docs link to gammfit classes
Fix a few PEP8 warnings
Added Crab MW dataset
Merge pull request #138 from rbuehler/crab_flux_points

Added Crab MW dataset
Rename README to README.rst and add line breaks
Implementation of morphology models as astropy models and testing
Docstring fixes and normalization option
Fixed handling of warnings in eval function and added TODO statement
Fixed doc links
Merge pull request #122 from adonath/shell2d_model_#115

Implementation of morphology models as astropy models and testing
Add crab_mwl SED dataset as one FITS file
Merge branch 'master' of github.com:gammapy/gammapy
Sqrt stretch colormap_hess
Script for model image computation