out the algorithm outlined on confluence.
makefile: adding MOAB lib as a dependency, and mbcoupler lib
  to libs for DeformMeshRemap

ElemEvaluator: hardwiring the number of tuples in a few cases where we know
  coords is the field we're evaluating; also changing the name of a few params from
  tag_dim to tagged_ent_dim to be more descriptive

LinearQuad: fixed jacobian scaling so J(2,2) is 1 instead of .25 (otherwise Jacobian for
  ideal cube is wrong)
SpatialLocator: added par_locate_points function, with no definition yet; also commented more fully,
  to describe use of SpatialLocator and assumptions made, and distinguishing serial vs. parallel use
test/elem_eval_test: added test for linear quad, and corrected test for avg position to divide by elem volume
test/spatial_locator_test: corrected arg order for SpatialLocator::locate_points
tools/mbcoupler/DataCoupler: new class analagous to Coupler that takes advantage of new SpatialLocator functionality