adding support in solver for adding services to an existing
cluster. Refactored most of the search logic into the
SlottedCombinationIterator, also adding slot max logic in the
process so that we don't needlessly search solutions when the max
has already been violated. Also created a ClusterLayout object
instead of working with maps of NodeLayout to Integer.
Adding some validation to make sure services being added to a
cluster are allowed to be added.
style fix of intellij generated code.
few classes missing license.
adding comment.
Merge pull request #65 from continuuity/feature/solver-add-service-to-cluster

Feature/solver add service to cluster