scoped session factory
use Session in loadtest view
Merge branch 'master' into coredb

Conflicts:
	corehq/apps/hqadmin/views.py
use nicer with-syntax for multimedia zip
extract zip and media file iteration from DownloadMultimediaZip
add multimedia to offline install

implemented by refactoring DownloadMultimediaZip and then subclassing

this required moving a fair amount of code around to get rid of import cycles
add a local authority to media resources for offline install
put only the right profile file in .ccz

- exclude everything except media_profile.ccpr
- name that file profile.ccpr
Add missing import
limit offline install changes to >=2.13 apps

- only include a local authority on media resources starting on 2.13
- only include the offline install option in ui starting on 2.13 apps
- pull out all enable_* methods of Application that check for feature
  support into a separate mixin, and have these methods available to
  SavedAppBuild for use in releases page
improve wording for Android Offline Install feature
Begin ESQuery class
Working ESQuery builder
move offline android install ui into Download to Android
decouple filters more and split out results class
moved es directory to an app
added some basic tests
Fix builtin_filters and reorganize a bit
Finish basic tests
Document usage