refactor macros: lifting is out, hoisting is in

[micha]

• Instead of lifting intermediate cells inside formulas, references to cells are hoisted out and the entire expression wrapped in an anon fn and that is lifted.
• Add defc and defc= macros.
• Use @cemerick cljs.test for testing.
• Attempt to fix console logging in phantom and headless ff.
• Rewrite cell= and defc= macros.
• Remove special handling of fn*.
• Avoid creating anonymous cell in set-cell!= because memory leaks.
• Unsupported specials are now down to just ns, def, deftype*, and defrecord.