Add CONTRIBUTING.md file.
Interpreter: Add traceur path and flags to process.execArgv.

BUG=https://github.com/google/traceur-compiler/issues/227
Fix 'for (let i = foo; bar; baz) single statement;'.

- Fix indentation of 'var transformedForLoop = ...'.

BUG=https://github.com/google/traceur-compiler/issues/231
TEST=test/feature/Scope/BlockBinding11.js
Merge pull request #232 from usrbincc/block-binding-for-loop-single-statement

Block binding for loop single statement
Update CONTRIBUTING.md

Fixed typos
Fix reading files on windows.

Add to Authors file.
Merge pull request #233 from peterhal/master

Make build-test-list work on Windows.
Add isStopIteration to '@iter' module. Update the tests to use it.

BUG=None
TEST=test/feature/Yield/GeneratorClose.js
     test/feature/Yield/GeneratorSend.js
     test/feature/Yield/GeneratorReturn.js
     test/feature/Yield/GeneratorThrow.js

Review URL: https://codereview.appspot.com/7610045
Patch from Ben Chan <usrbincc@yahoo.com>.
Fix setting of StopIteration and GeneratorReturn.

- Set the global StopIteration correctly in the 'undefined' case.
- Use getters so that the effects of setStopIteration, etc, show up in
  traceur.runtime.StopIteration, etc. Previously it was only updated
  during runtime initialization.

BUG=None
TEST=test/feature/Yield/StopIteration.js

Review URL: https://codereview.appspot.com/7757044
Patch from Ben Chan <usrbincc@yahoo.com>.