Renamed package name to synphot, so that it will be astropy.synphot when merged into astropy. Reorganized codes to how astropy is organized, so that transition from affiliated package to sub-package is easier. Renamed pysynexcept module to synexceptions for clarity. Disabled test_simple.py because any test will not work until codes are completely refactored (ongoing work in a different branch).
Merge pull request #40 from pllim/rename-package

Renamed package name to synphot, so that it will be astropy.synphot