Adding plugin resource sync. Every time a sync is called, every
resource that is set to go live is found and sent to every
provisioner that has workers assigned to it for that tenant.
add missing javadoc and fix checkstyle errors.
fix put tenant call to provisioners.
explicitly exclude undesired field when serializing resource
collection and sending to provisioner.
fix a sync race condition and a bug where the metadata for
resource types that dont get synced are not updated, which can
prevent resources that are unstaged to transition to the
inactive state.
make sure stage/unstage on nonexistent resource returns a 404.
removing sync lock and explicitly setting which resources are
live instead of trying to coordinate when a stage/unstage has
to happen in relation to a sync.
Merge remote-tracking branch 'origin/develop' into feature/resource-sync

Conflicts:
	server/src/main/java/com/continuuity/loom/http/handler/LoomPluginHandler.java
	server/src/main/java/com/continuuity/loom/provisioner/plugin/ResourceService.java
	server/src/test/java/com/continuuity/loom/http/LoomPluginHandlerTest.java
Merge pull request #325 from continuuity/feature/resource-sync

Adding plugin resource sync. Every time a sync is called, every