Adapt TilingComposite to Pegasus architecture

[arcondello]

Right now the TilingComposite is only defined for Chimera-structured hardware graphs.

See also #294

[jackraymond]

TilingComposite has been modified so that Chimera structured subproblems can be tiled over Pegasus-structured graphs. This is a partial solution. #431
The ability to tile Pegasus structured subproblems over Pegasus structured graphs is still absent. This involves changes to the class signature, amongst other things.

[jackraymond]

It would make sense to have a simpler DisplacementComposite or AutomorphicComposite that attempts to move/rotate an embedding on the processor. This would have independent value for noise reductions (same reason as SRT). The TilingComposite would reuse these transformations (accumulating them subject to no intersection)
.