Improved numeric constants highlighting.
Fixed #14.
Fixed single line where indenting.
Moved several modern Fortran keyword in Punchcard to Modern. Added select type construct.
Added associate construct to Modern Fortran. Fixed #15.
Fixed public/private keyword highlighting.
Fixed intent attributes.
Updated type specification rules.
Added procedure attributes to Modern Fortran.
Fixed some exceptions left over from last few commits.
Added error checking to function, subroutine, and module end statements.
Added error checking to program end statements.
Merge pull request #16 from tomedunn/master

Several small improvements.