added catch for NullPointerException
adapt license files

additionally enable more logoutput for sourcetests in console
Merge pull request #1054 from Catrobat/CAT-1100

cat-1100 #fixed 
adapt license files
Introduced ConcurrentFormulaHashMap to BrickBaseType
Introduced custom xstream converter to support porting old projects' code.xml to new structure of code.xml
Converted FormulaBrick.java from interface to a class Converted NestingBrick.java from abstract to interface All the DroneBricks are extended by BrickBaseType.java
Replaced Formulas in DroneMoveBrick.java with ConcurrentFormulaHashMap
Refactored DroneBricks
Added testTurnLeft and testTurnRight methods to DroneBricksActionTests.java
Converted LoopBeginBrick.java to an interface. Fixed an error in ForeverBrick.java
Updated LoopBrick tests
Converted VibrationBrick to support ConcurrentFormulaHashMap. Added clone test of VibrationBrick.java to BrickCloneTest.java
Fixed issue in ForeverBrick.java and updated tests
Updated test cases in DroneMoveTest.java
Removed old testBrickWithFormulaEditor method from UiTestUtils.java
Fixed issue in testCopySprite
Converted FormulaBrick to an abstract class
Removing sprite references from Bricks and Scripts
Fixed errors and PMD warnings
new structure of code.xml
do not write references to loop and if bricks to xml
Change the order of the fields in sprite
Removed loopEndBrick, loopEndlessBrick, ifElseBrick and ifEndBrick references from old code.xml
Fixed testProjectSameAsStandardProject test
Renamed sprites to objectList, spriteVariableList to objectVariableList and sprite to object
Converted scriptNodes to support type attribute