mostly working initial implementation of drawing module
improved drawing modules
Merge pull request #11 from ahovgaard/drawing

Drawing modules: DrawingSvg and DrawingLatex.
minor improvements to Drawing modules
parsing of multiple value declarations with bindings
added checking of nullary tycons
added checking of all tycons
minor improvements to parser
Merge pull request #12 from ahovgaard/parserChecking

Added more checking to parser