CostFunction classes rewrite to use the new API (package broken)
Rewrite Matrix module (package still broken)
Add test for lapjv module
Solver classes rewrite

All tests pass now. I wait for you approbal before I merge it.
Add warning message to README and doc about sktracker being in very early stage development
Merge branch 'merge_cost_func_block' of github.com:hadim/scikit-tracker into merge_cost_func_block

Conflicts:
	README.md
	sktracker/tracker/solver/by_frame_solver.py
	sktracker/tracker/utils/tests/test_scores.py
passes the tests