Hopefully most recent set of changes, including each sparse with indices for yale.
Fixed compiling on Carlos' branch
Fixed bug introduced by @agarie's pull request.
Merge branch 'dev'
Yale: each_sparse_with_indices, including specs for dense and list implementations (pending)
Fixed yale each_sparse_with_indices iteration. Prepared to implement version for dense.
Renamed each_sparse_with_indices to each_stored_with_indices. Added dense functionality, updated spec; doesn't seem to get the i index right, but almost there.
Fixed bugs with each_stored_with_indices (dense)