added catch for NullPointerException
Merge pull request #1073 from Catrobat/cat-930

[CAT-930] added catch for NullPointerException
CAT-930 #close
Implemented FaceDetection and Camera support
Fixed FaceDetection
compatibility of Led Brick (Singleton Camera)
Merge pull request #1081 from Catrobat/restoreFacedetection

Restore facedetection
fixed CAT-531

added try/catch to location of possible exceptions