Disable experimental GREEDY* methods in Faust optimize_time, keeping only GREEDY_ALL_BEST_GENMAT.

Deleting them explicitely in wrappers (in FaustMulMode class) even if they are still available (but hidden) from the C++ core.
In wrappers GREEDY_ALL_BEST_GENMAT is renamed GREEDY for simplification.
The choice to remove them is made after conclusive benchmarking.
Documenting the C++ FaustMulMode and adjusting the wrapper versions too.