Save partial results after 5 minutes

Besides saving partial results after 500 repetitions, also save the
partial results after 5 minutes since the last time the partial results
were saved.
Improve the simulator for the greedy algorithm
Increase max n° of iterations to find mu

Increase maximum number of iterations of the Newton algorithm to find
the optimum Lagrange multiplier in the MMSE based IA algorithm
Small changes to make it compatible with python 3

Small changes to make it compatible with python 3 at the same time it is
compatible with python 2.