Bug fix in get impostors function.
Index of the target neighbour was wrong in the impostors triplet
LMNN complete with results obtained comparable to the original implmentation.
Change of interface in outer products operations to avoid recalculations
of outer products.
Bug fixes in top-level LMNN and in PSD projection.
New function to compute LMNN objective.
Simple demo to compare results by original LMNN implementation, our
LMNN prototype, and Euclidean distance.