Add COM port as engine configuration rather than hardcode.  Make connection to G2 optional to run the engine.
Merge branch 'dashboard' of https://github.com/ShopBotTools/FabMo-Engine into dashboard

Conflicts:
	config/default/engine.json
App editor functionality (unfinished)
Merge branch 'dashboard' of https://github.com/ShopBotTools/FabMo-Engine into dashboard