Add test with export * leading to duplicate export
Add debug target to build sourcemap

Review URL: https://github.com/google/traceur-compiler/pull/467

Closes #467.
Fix conflict issue with alpha renaming of this in arrow functions

By doing the alpha renaming in the outer function first we do the renaming of inner arrow functions too.

Fixes #466

Review URL: https://github.com/google/traceur-compiler/pull/468

Closes #468, closes #466.
Close GH-472: Refactor ProgramTransformer into FromOptionsTransformer and ProjectTrans....
Unify transformer constructor type signature

This allows us to remove a bunch of boilerplate code.

Review URL: https://github.com/google/traceur-compiler/pull/473

Closes #473.
Fix parsing of arrow functions

Arrow functions should be parsed as AssignmentExpression, meaning that they have the lowest precedence of them all.

Review URL: https://github.com/google/traceur-compiler/pull/464

Closes #464.
Change code gen for module getters

This changes the code gen for modules to return a simpler object literal. If someone asks for a module instance object, using `module ident from 'name'` or `System.get('name')`, we create the `Module` object at that point.

The benefit for this is that we now have a smaller code gen and it allows follow up changes to dynamically do `export * from 'name'`.

Partial fix for #470

Review URL: https://github.com/google/traceur-compiler/pull/474

Closes #474.
Dynamic export star

Introduce a runtime function that handles `export *`.

This allows us to not need the module symbol at all in the transformation phase.

Fixes #470

Review URL: https://github.com/google/traceur-compiler/pull/475

Closes #475, closes #470.
Fix minor typo from last commit
Merge branch 'master' into annotations

* master:
  Fix minor typo from last commit
  Dynamic export star
  Change code gen for module getters
  Fix parsing of arrow functions
  Unify transformer constructor type signature
  Close GH-472: Refactor ProgramTransformer into FromOptionsTransformer and ProjectTrans....
  Fix conflict issue with alpha renaming of this in arrow functions
  Add debug target to build sourcemap
  Add test with export * leading to duplicate export
Merged with latest master changes