remove CaseBase class

it wasn't really adding any value and made it much more annyoing to see
the list of properties on the case model.

this change also properly changes referrals to DocumentSchema, instead
of Document and moves the case-specific to_full_dict function into that
class as well.
Merge pull request #218 from dimagi/pretty-user-display

tweak user display
Return 412 instead of 404 on bad sync.
Merge pull request #224 from dimagi/return-412

Return 412 instead of 404 on bad sync.
mark date properties as not being UTC for display

this reflects our doing a terrible job of keeping track of timezones
in form and case data.

these values will be interpreted as "local time" whatever that is for the domain
Merge pull request #225 from dimagi/case-display-tz

mark date properties as not being UTC for display
Merge pull request #222 from dimagi/kill-case-base

remove CaseBase class
Revert "Return 412 instead of 404 on bad sync."

This reverts commit e06d1d5f2df6a593380f791336af6acc0094e693.
raise 412 instead of 404 from sync log
add new django-no-exceptions dependency to travis
add explicit redis dependencies
Merge pull request #227 from dimagi/explicit-redis-dep

add explicit redis dependencies
Merge branch 'master' into sync-log-412
remove 2.6 travis target
Merge pull request #228 from dimagi/2.7-only

remove 2.6 travis target
Merge branch 'master' into sync-log-412
Merge pull request #226 from dimagi/sync-log-412

Sync log 412
Add search fields to stock models
Merge pull request #229 from dimagi/search_fields

Add search fields to stock models
Group XForm lookups in case.get_forms