TCV: check Object as Array-Content-Type
Monty.g4/ASTBuilder remove deprecated operator[]

For Monty 1.0 the array-access will be done using the method get().
Remove deprecated function operator[] from Array.monty
Remove deprecated translation in NMV (operator[])
Add Array as corelib class
Remove deprecated TypeConverter.addArray()
Implement Array as Object-array
Implement (un)boxing for Arrays
CodeGenerator: change visibility of {resolve,cast}IfNeeded

These methods need to be visible in Operations later.
Operations: Implement Array.length()
Operations: Implement Array.set()
Operations: Implement Array.get()
Modify and enable old Array-Tests
Test cases for Array-constructor
Test cases for Array as Object
Test cases for Array.length()
Merge pull request #7 from lummax/boxed_array_implementation

Boxed array implementation
Add FEATURES.md
Link FEATURES.md from README.md
Add HACKING.md