Changes for new app engine release

Change all imports of the endpoints library
Change app.yaml to include library in examples
Trying to implement resource containers
Stupid fix...
Fix docs
Refactoring and reformating, caching ResourceContainers

Moved message_fields creation to a separate method.
Reformated to make lines shorter.
Caching ResourceContainers (separate from proto models and collections)
Fix key for caching ResourceContainer
Merge pull request #80 from Scarygami/master

Fixes for new app engine release (import endpoints and ResourceContainer)
Merge branch 'master' of github.com:GoogleCloudPlatform/endpoints-proto-datastore