Solidity parser - not polished yet, but usable

First shot at the solidity parser. It generates an AST and infers and checks the types for each expression node.

Mappings and structs are parsed, but not yet integrated into the type system.
CS: remove space before :
probably a million more like all these. please go over the CodingStandards.txt and the patch and make sure it's in line with all coding conventions used in the codebase.