Small fixes for the summer (rebased)

Rebase of #675 post-schema-simplification.  Original comments copied:
This is a set of small changes I made recently, mostly for old tickets that I thought were still useful and easy:
#32 Lottery reg statistics in Ajax class status on dashboard
#47 Gender field for student profile
#48 Schedule information on user view page
#131 Approved classes in teacher profile
#183 PDF catalog view
#223 Class approving from registration e-mail
#228 Replace custom PhoneNumberFields
#232 Consistency with MEDIA_URL usage
#323 Allow complete availability in classroom import
#398 Timeslot import from a previous program
#545 Zip codes aren't populated by default
#601 "Generate list of users" uses old comm panel

Please review and recommend any needed tests.