fix DRONE-15

deactivate Drone with Feature flag
improve Gradle build Feature output
add LegoNXT build flag
fix typos
Merge pull request #989 from Catrobat/DRONE-15_drone_buildflag

DRONE-15 - buildflag
bricks, utils and layouts copied
modified files that could cause merge conflicts
testclasses copied
Merge branch 'vibration_and_led_brick' of https://github.com/Catrobat/Catroid into vibration_and_led_brick