Enhance the merge glts algorithm.
* Weaken disjoint :origin by disjoint :invariants
* Remove the :origin decoration
* Perform an edge_count based scoring.
Add State and Edge modules for automaton utils injection.
Add Glts#end_state
Add computation of transitive closure through decoration.
Add tests for State and Edge modules.
Tclosure
Add a Glts#trim algorithm that removes unreachable states and edges.
Fix minimize and ensure it trims the automaton.
Trim glts in pre-merge.
Add support for nop_st in Ast2Graph
Remove Glts#o debuging
Add Glts:State#decision?
Start Glts parsing -> AST
Enhance --glts=ruby output.
Resurect main task events.

Determinization + minimization otherwise introduce guard problems
on single while loops tasks (the false path does not generate any
event and is thus trimmed in the process).