- rename atrim to atrim.fsm
 - Terminology - redundant state is now dead state
 - allow to remove only unreachable or only dead states (see ./atrim.fsm -h)
 - remove namespace

Destruction of everything.
Merged following from conversions:
 - derivations and integrals
 - conversions FA-RE and FA-RG

Algebraic Method: decrease memory consumption by reducing regexp trees on the fly (side effect: speedup)

 - Rewrite elimination
 - Eliminate from deepest states towards initial state (BFS is run)
 - fix leaks