Add SIDE_HIERARCHIC support for triangles
Add SIDE_HIERARCHIC support for triangles

My attempt at analytic gradients doesn't seem to be working at all, so
let's start with FDM gradients and Hessians

dschwen/libmesh,dschwen/libmesh,dschwen/libmesh,libMesh/libmesh,libMesh/libmesh,libMesh/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,libMesh/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,libMesh/libmesh,dschwen/libmesh,dschwen/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,dschwen/libmesh,dschwen/libmesh,libMesh/libmesh,jwpeterson/libmesh,libMesh/libmesh,BalticPinguin/libmesh,dschwen/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,libMesh/libmesh