Add Lagrange interpolation optimization
Add Lagrange interpolation optimization

This fixes a unit test failure for me, hopefully fixes any code
further downstream that was relying on our previous
interpolation-vs-projection behavior, and ought to avoid us
pessimizing those cases.

hrittich/libmesh,libMesh/libmesh,capitalaslash/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,dschwen/libmesh,BalticPinguin/libmesh,pbauman/libmesh,pbauman/libmesh,BalticPinguin/libmesh,hrittich/libmesh,90jrong/libmesh,jwpeterson/libmesh,pbauman/libmesh,libMesh/libmesh,capitalaslash/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,roystgnr/libmesh,roystgnr/libmesh,hrittich/libmesh,roystgnr/libmesh,dschwen/libmesh,hrittich/libmesh,libMesh/libmesh,jwpeterson/libmesh,90jrong/libmesh,90jrong/libmesh,jwpeterson/libmesh,pbauman/libmesh,BalticPinguin/libmesh,pbauman/libmesh,hrittich/libmesh,90jrong/libmesh,90jrong/libmesh,jwpeterson/libmesh,pbauman/libmesh,libMesh/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,hrittich/libmesh,dschwen/libmesh,BalticPinguin/libmesh,capitalaslash/libmesh,hrittich/libmesh,libMesh/libmesh,pbauman/libmesh,libMesh/libmesh,hrittich/libmesh,90jrong/libmesh,libMesh/libmesh,pbauman/libmesh,libMesh/libmesh,BalticPinguin/libmesh,hrittich/libmesh,jwpeterson/libmesh,capitalaslash/libmesh,roystgnr/libmesh,dschwen/libmesh,dschwen/libmesh,BalticPinguin/libmesh,roystgnr/libmesh,capitalaslash/libmesh,90jrong/libmesh,roystgnr/libmesh,pbauman/libmesh,roystgnr/libmesh,90jrong/libmesh,capitalaslash/libmesh,roystgnr/libmesh,90jrong/libmesh,dschwen/libmesh,dschwen/libmesh,dschwen/libmesh