Beginnings of new plugin registration system, for issue #5
Possible changes to joyent_provider JSON for plugin registry
Possible changes to rackspace_provider JSON for plugin registry
Proposed changes to openstack_provider JSON
Adding labels
Make security_groups required
Add back old layout, to make plugins backwards-compatible
Whitespace
Updated JSON with latest proposed solution for issue #5
add callbacks before and after cluster operations. Refactoring
some common logic into TaskService to make sure the before and
after hooks are isolated to a single class.
Merge branch 'develop' into feature/plugin-registry-via-json
Adding provider type and automator type as their own entities so
that plugin writers can define what fields their plugins need
and what type of value each field expects.
updating test json objects for integration tests.
updating pluginmanager to handle new json format with existing server impl
Merge remote-tracking branch 'origin/develop' into feature/add-provider-automator-type
updating cluster definitions json for integration tests.
Merge remote-tracking branch 'origin/develop' into feature/http-callbacks

Conflicts:
	server/src/main/java/com/continuuity/loom/scheduler/JobScheduler.java
	server/src/main/java/com/continuuity/loom/scheduler/task/TaskService.java
	server/src/test/java/com/continuuity/loom/scheduler/SchedulerTest.java
adding client and server
separate into start, success, and failure events instead of just
before and after.
base api changes for provisioner registration fields