Add command line option --module <module-name>.

  Allows scripts and modules to be compiled in any order.

Review URL: https://github.com/google/traceur-compiler/pull/1064

Closes #1064.
Only add System.get() evaluator for modules=register.

Fixes #1066

Review URL: https://github.com/google/traceur-compiler/pull/1067

Closes #1067, closes #1066.

Added copyright notes.
Merge branch 'master' of https://github.com/sadaszewski/traceur-compiler