Automatically execute -main and add sys.argv's

"Interesting" ideas:

1. Have a main function automatically execute (as in clojure).  
  * Rationale: The clunkyness of `(if (= __main__ "__name__") ....)` is and will always be ugly. The idea is to have a special name as clojure does (in this case we ripoff `-main`) which gets automatically executed, by having the special function name, we can still use the old idiom if we wish.

2. Add sys.argvs automatically into the `-main` function header.  
 * Rationale: It is awsome.