Fix bug 468: generalize UmfPack support to accept any input at the cost of an implicit copy.
Fix bug 468: generalize UmfPack support to accept any input at the cost of an implicit copy.

cjntaylor/eigen,pthulhu/eigen,cjntaylor/eigen,pthulhu/eigen,cjntaylor/eigen,pthulhu/eigen,pthulhu/eigen,pthulhu/eigen,cjntaylor/eigen