upgrade to groovy 2.2.0
Merge branch 'master' of https://github.com/canoo/dolphin_train_station

Conflicts:
	shared/src/main/groovy/com/canoo/codecamp/dolphinpi/DepartureConstants.groovy
Merge branch 'master' of https://github.com/canoo/dolphin_train_station

Conflicts:
	gradle.properties
	shared/src/main/groovy/com/canoo/codecamp/dolphinpi/DepartureConstants.groovy
Merge branch 'master' of https://github.com/canoo/dolphin_train_station
Merge branch 'master' of https://github.com/canoo/dolphin_train_station
reactivated color highlighting for invalid fields
improved startup behavior
some bug fixes