Some tests for additional mathematical functions
Added additional mathematical functions
Added strings to values-de
Merge branch 'master' into testAdditionalMathFunctions

Conflicts:
	catroid/res/values-de/strings.xml
	catroid/res/values/strings.xml
	catroid/src/org/catrobat/catroid/formulaeditor/FormulaElement.java
	catroid/src/org/catrobat/catroid/formulaeditor/Functions.java
	catroid/src/org/catrobat/catroid/formulaeditor/InternFormulaKeyboardAdapter.java
	catroid/src/org/catrobat/catroid/formulaeditor/InternToExternGenerator.java
	catroidTest/src/org/catrobat/catroid/test/formulaeditor/ParserTestFunctions.java
Merge branch 'master' of https://github.com/Catrobat/Catroid into testAdditionalMathFunctions
Merge pull request #371 from TDiva/testAdditionalMathFunctions

Additional mathematical functions