TODO
----

 * Read a configuration file and pass this to rules that want
   information. Possibly read in a file into a 
   map<std::string, std::string> and then have a function
   const std::string request_option(const std::string option)

 * Should we create an output file is one is specified, so that 
      
      # make CXX=clint
   
   will work.

 * Get pre-processing working satisfactorily
   Nothing currently works. we need to get #include workign at least

 * hook up a parser so the we can get access to type information
   This is the biggest feature that is needed. Once we have this we can
   then write tests to check the symbol table and the parse tree.

 * create a function to find the current nested level. It may be worth
   adding a function to the rules to allow them to perform an action
   when the nested level changes. This would allow us to test things
   are still in scope.