Added cell characteristic function.
Added CellCharacteristicFunction.
Added DRAFT GoalOrientedRefinementStrategy.  DOES NOT WORK!  (needs a global dual solve.)
Added (commented out) line for goal-oriented option, which does not yet work anyway.
Messing around with StokesCavityFlowDriver, including goal-oriented stuff.
Made the partition argument in elementsInPartition optional (defaults to current MPI rank).
Merge branch 'master' of github.com:CamelliaDPG/Camellia
Fixed up NavierStokesHemkerDriver with different defaults, as well as richer CLI options (in particular regarding control of the domain geometry).