Added support for lua debugger

Added the ability to invoke the lua debugger at startup, I find it useful when debugging my custom tool chain and code gen actions.

I also expandeded a little bit on the error message, if you invoke --lua-debugger instead of action first, you get error `unknown action '--lua-debugger'` instead of just `unknown action`

I made it so that the action name still has to be first, but the --lua-debugger part can occur anywhere after the action and won't be forwarded to the actions, so it will not integer with their command line processing.