Problem: Need private classes and constants
Solution:
   * Add new tag to make classes private
   * Added wrapper for private classes
   * Added constants to private classes
   * Don't distribute header of private classes
Merge pull request #4 from sappo/master

Problem: Need private classes and constants
Problem: Documentation is incomplete 

Solution: Add more documentation :)
Problem: There's no obvious way to figure out what a gsl file generates
Solution: Add a summary of the files the gsl script generates at the top
of the file as a comment.
Problem: Public constants aren't recognized
Solution: Add public constants to the main project header
Problem: The shell scripts have no shebangs
Solution: Add to each the line: #!/usr/bin/sh
Merge pull request #6 from jemc/master

Problem: The shell scripts have no shebangs
Merge pull request #5 from sappo/master

Problem: There's no obvious way to figure out what a gsl file generates
Problem: Current shebang wont work cross platform
Solution: Change shebang to `/usr/bin/env sh` for cross platform support
Merge pull request #9 from sappo/master

Problem: Current shebang wont work cross platform