More efficient ordering of constrained DoF index sets
Merge branch 'master' of github.com:libMesh/libmesh
Merge branch 'master' of github.com:libMesh/libmesh
Merge branch 'master' of github.com:libMesh/libmesh
Merge branch 'master' of github.com:roystgnr/libmesh
adding MeshfreeInterpolation class
adding InverseDistanceInterpolation & misc_ex8 to demonstrate usage
adding nanoflann as a contributed package.

nanoflann is a BSD-licensed C++ header-only library for building
KD-Trees, mostly optimized for 2D or 3D point clouds. Queries for
neighbors around any arbitrary location in space can then be solved
quickly and efficiently using Approximate Nearest Neighbor (ANN)
algorithms.

http://code.google.com/p/nanoflann
incorporating nanoflann into our build system
updating generated files from previous commit, separately so as not to bloat the diff
Merge branch 'master' into meshfree_interp
Updated InverseDistanceInterpolation class to use an internal KD-Tree.

This will need to be updated for the parallel case where we want to
allow for source data on remote processors - and I have an idea how to
do that - but I'm leaving that part for future work.
examples/miscellaneous/miscellaneous_ex8 demonstrates usage so far.

not actually interpolating yet.
Actually perform inverse distance interpolation.  Also interpolate two
different variables in the example to verify that functionality.
extend miscellaneous/miscellaneous_ex8 to do interpolation from one mesh to another
Merge branch 'master' into meshfree_interp
pass distcheck
Merge branch 'master' into meshfree_interp
incorporated m4 fixes
demo a MeshlessInterpolationFunction in miscellaneous_ex8.C
Merge branch 'master' into meshfree_interp