Merge pull request #19 from lgwagner/master

add tuple expressions to allow multiple value node calls within a sub ...
Remove debugging code
Improve type error messages for variable assignments
Simplify FlattenCompoundTypes
Clean up InlineNodeCalls
More code clean up
Generalize flatten tuples and remove some bugs
Refactor flattening of arrays and records
Group all translations in a single function
Reorganize files
More refactoring of array and record removal
Code refactoring
Factor out common front end code
Clean up naming of properties in examples