Merge pull request #54 from dimagi/cz

fixes to the previous
fix dates.py import to work with celery >=3.0.0
allow for classes without a domain attribute to subclass UndoableDocument
Merge pull request #55 from dimagi/domain-included

allow for classes without a domain attribute to subclass UndoableDocumen...
fix this so that it doesn't take away 1 second...eeeh????????
Merge pull request #56 from dimagi/date-offset-fix

fix this so that it doesn't take away 1 second...eeeh????????
Pass on CC to Django email message class
Merge pull request #57 from kennknowles/case-45560-cc-inviter

Pass on CC to Django email message class
Use configured Django email backend (by omitting params)
Merge pull request #58 from kennknowles/use-default-email-backend

Use configured Django email backend (by omitting params)
upgrading logger for celery upgrade
add a timeout to simple_post
pep 8 etc cleanup
Merge pull request #59 from dimagi/simple-post-timeout

Simple post timeout
Merge branch 'master' into celery-upgrade
Merge pull request #60 from dimagi/celery-upgrade

upgrading logger for celery upgrade
make celery log import more version-tolerant