Add tevpy/detect/sex.py
Add tevpy/detect/sex.cfg
Add tevpy/detect/sex.param
Add tevpy/detect/tests/test_sex.py
Move tevpy/data/poisson_stats_image files to tevpy/data

This is a temp fix because having sub-folders currently
is not possible ... I files an astropy issue
Fix test error with get_package_data in sex.py
Move data files back to sub-folder ... it works now.
Add setup_package.py to data sub-module
Add setup_package.py to detect sub-package
Move files in place in tevpy/data
Fix setup.py package_data entry
Add license line to setup_package.py files
Add test files for data sub-package
Add more files to poisson_stats_image example
Add test for poisson_stats_image with extra_info=True
Minor update to SExtractor wrapper function
Uncomment SExtractor test for now as it doesn't work
Add short description to top-level tevpy docstring
Add docs for data sub-package