Things to do (Things that are not done yet)

* Here document
* Special variables ($1,$2..)
* super in aliased methods
* BEGIN/END (Were we not supporting this?)
* const_missing
* respond_to_missing

Things to improve (Done but things to fix)

* Hash (Reduce size. Use khash or save the order)
* stringEx (Delete encoding、delete CODERANGE、delete everything except UTF-8 or ASCII)
* Make additions as they are noticed.