adding ability to reconfigure an active cluster.
cluster reconfig form
adding json modifier
json validation added
add ability to add services
adding reconfigure-cluster to this branch
adding ability to plan jobs for a delta of the services and/or
nodes in a cluster to support cluster operations that act on an
existing cluster. Additionally, refactored most of the job
planning logic from the ClusterScheduler into a new JobPlanner
class.
close resources in SQLClusterStore where they are created,
cleaning up a comment, and moving the set of configurable states
to the cluster status.
Merge branch 'feature/reconfigure-cluster' of github.com:continuuity/loom into feature/reconfigure-cluster
Merge pull request #64 from continuuity/feature/reconfigure-cluster

adding ability to reconfigure an active cluster.
Merge remote-tracking branch 'origin/develop' into feature/planner-on-service-subset

Conflicts:
	server/src/main/java/com/continuuity/loom/scheduler/Actions.java
	server/src/main/java/com/continuuity/loom/scheduler/ClusterAction.java
	server/src/main/java/com/continuuity/loom/scheduler/ClusterScheduler.java
	server/src/test/java/com/continuuity/loom/scheduler/JobPlannerTest.java
adding more documentation.
Merge pull request #66 from continuuity/feature/planner-on-service-subset

adding ability to plan jobs for a delta of the services and/or
Merge remote-tracking branch 'origin/develop' into feature/add-different-types-of-solve-tasks

Conflicts:
	server/src/main/java/com/continuuity/loom/codec/json/JsonSerde.java
	server/src/test/java/com/continuuity/loom/http/LoomClusterHandlerTest.java