Merge pull request #5 from mightymoose/master

Fix Typo
Merge pull request #6 from mightymoose/master

Add lexing floats.
Merge pull request #7 from mightymoose/master

Add parsing of simple math operations.
Merge pull request #8 from mightymoose/master

Added parenthesis lexing.
Merge pull request #9 from mightymoose/master

Split up Multiply and Add
Merge pull request #10 from mightymoose/master

Add simple parsing rules.
Merge pull request #11 from mightymoose/master

Add simple interpreter.
Merge pull request #12 from mightymoose/master

Added a silly command line usage.
Add to pypi.
Now reading and executing files.
Now correctly handing multi line programs.
Now lexing and parsing identifiers and assignment.
Implement simple global variables.