Begins adding CHOICES to ClassSubject and ClassSection

see issue #1263
More switching things to use STATUS_CHOICES
More adding STATUS_CHOICES to things

wheee
more standardizing
Revert "more standardizing"

This reverts commit aa131e8a827ef43e30765971a400983e9933b3f6.
Revert "More adding STATUS_CHOICES to things"

This reverts commit 1a7203651002c38826257a8fff98173e2da548b8.
Revert "More switching things to use STATUS_CHOICES"

This reverts commit eae9d0f7b991779e6e17f7c22669fa603d3be609.
Merge branch 'add_choices' into admin_py_stuff

Conflicts:
	esp/esp/program/models/class_.py
replaced yak
fixed typos