Implement code gen for relational expressions
Apparently bools can be compared with less than/greater than
Output correct function names
Var declarations get a newline
Fix issue where .var directives had wrong type signature
Made local vars start at 0
Fix ".var" causing "pop on empty stack" errors
Fix issue where generated labels had dashes
Add a little more information on using Decaf
Merge pull request #57 from hawkw/codegen

Merge additional documentation