Added MBMonad type class.

Unifies common functionality of the MB and Trigger monads.
Merge branch 'master' into mapper
Mapper: Implemented showJSON for the map types.
Mapper: Added the map to the global state.
Mapper: Added walker trigger flow.
Mapper: Load maps from file or string. Add shortestPath.
Screen/Gtk: Interpret all input starting with a colon as a command.
Core: Add 'modifyTriggers' to MB.
Merge branch 'master' into mapper

Conflicts:
	src/Mudblood/Core.hs
Main: Add commands "walk" and "loadmap".
Mapper: Added "mapMapGraph"
Core: Add UI action "UIUpdateMap"
Screen/Gtk: Print current room id in system status.
Mapper: Let the default map have at least one room.
Mapper: Add 'moveTrigger'.
Mapper: Fix UIUpdateMap
Core: Add GetMap/PutMap to Trigger interpreter.
Core: Process send triggers.
Main: Add moveTrigger to trigger flow.
Merge branch 'master' into mapper