Add check for outgoing place capacities
Comment Pnml annotation
Create arcs with actual type rathet than Connectable

* Add tests
Use Java generics to aovid casting arc source and target

Fix bug in forwards/backwards incience matrix creation that is also in PIPE 4
Add test for firing transition when arc marked with 0
Changed arc model. It is now a single class with different strategies for firing
Petrinet now fires inhibitor arc correctly

* Remove InhibitorArc and NormalArc class
* Add ArcType enum
* Add tests for inhibitor arc
* Leave in some view firing things, but just stubbed out for compliation of classes
* Modify tests