Auto generate the import for ParseTreeTransformer

Review URL: https://github.com/google/traceur-compiler/pull/440

Closes #440.
inline module runtime helpers

This is a first step towards https://github.com/google/traceur-compiler/issues/437, just supporting the standard helper inlining for modules as is given by scripts.

Review URL: https://github.com/google/traceur-compiler/pull/438

Closes #438.
Follow up change to RuntimeInliner

Review URL: https://github.com/google/traceur-compiler/pull/441

Closes #441.
Change class transformer to use hoisting
Rebase