Feature/al

[yury-lysogorskiy]

pyace:

• upd pace_activeset: add --error-force-threshold (default auto) and --all-atoms (default - False)
• add activeexploration.py
• bugfix singular matrix for active set calculation
• bugfix pace_activeset -e 0 default
• add active exploration (pyace.activeexploration.ActiveExploration + example) ace and ace-evaluator:
• upd multiarrays
• reduce gcc warnings, -Wvla