Labels are stored on the node record itself

WARNING: This change increases the store format version as well as the logical log version, but migration isn't supported yet.

o Integrated and working solution for storing node labels on the node record
  itself. If the in-record space isn't enough it will spill over to a
  dymamic array store dedicated for node labels.
o Javadocs on store migration
o Can create the node label store lazily to allow for a bridge until real migration is in place
o Refactorings/cleanup in store classes w/ regards to allocating/reading arrays