Refactor PointToBrick

Add option to create new Object from within ```PointToBrick```'s drop down list

Remove entry ```Nothing...```
Add entry ```New...```
Add test to ```PointToBrickTest```
Remove ```PointToBrick``` from ```EmptyBrickSpinnersTest```

Jenkins Testrun: http://catrobatgw.ist.tugraz.at:8080/job/Catroid-custom-branch-test/677/