Tpetra::CrsMatrix: Implement 2-arg "copy constructor" like MultiVector's
Created by: mhoemmen
@trilinos/tpetra Give Tpetra::CrsMatrix a two-argument "copy constructor" like MultiVector's. It should take an optional second argument that tells it whether to make a deep copy. If the graph is a const graph, it should be able just to copy the values.
If users want a "true deep copy" of the graph as well, the fix for #531 (closed) will offer that.