New working branch comÃÃÃpiler. Branch for math parsing.
Interpreter improvements.
fix
Update einmaleins.json
Update einmaleins.json
Update einmaleins.json
Update einmaleins.json
Improved interpreter.py

Removed debug code.
Improved code style with PEP8.
Added unittests for interpreter.py.
Removed files not needed anymore.
Removed pictures.
Fixed interpreter.py macro_randint.
Extended interpreter.py tests.
Fixed pep8 in tests/interpreter.py
Fixed bugs in interpreter.py found with the tests.
Added check_tree to Interpreter.
Added factorial.
Removed examples folder.
Merge pull request #1 from pyfisch/compiler

First stable version of math language interpreter