add elpy to the list of supported emacs implementations
test lists in Interpreter, #297
test for 3 part slice precedences
CompiledObject.get_index_types implementation example
implemented a first prototype of a slicing and index creation function
moved the input of get_index_types to a more typical type system
implement __getitem__ access for CompiledObject
more detailed tests and implementation of array indexing in the interpreter
negative factors like -1 are now evaluated
implement slicing for __getitem__ with interpreter