Refactor the command-line argument parsing (again)
This change allows the client of CmdLineParser a bit more flexibility, by giving him an arbitrary computation (not just a deprecation message) for each flag. There are several clients, so there are lots of boilerplate changes. Immediate motivation: if RTS is not profiled, we want to make Template Haskell illegal. That wasn't with the old setup.
Showing with 603 additions and 658 deletions