When the manifold dim is lower than embedding dim

[sjkoelle]

I found a couple bugs associated with the embedding dimension being greater than the manifold dimension, basically having to do with truncating the remaining singular values.

1. compute_G_from_H should be passing the manifold dimension as an argument (looks like its set up to do this but not doing it currently)

2. In compute_G_from_H (the 'elif mdimG < n_dim:' part) there are undefined variables and so forth. I don't think this has been tested. As is, it won't work for mdimG < ndim_Y.