Cleanup errback and Promise.cast
Add test for promise cast
Merge pull request #912 from arv/async-throw-state

Simplify async throw state
FindVisitor: Remove usage of try/catch for program flow.

Instead, override visitAny to do nothing if the condition was found
already.
Merge pull request #913 from arv/visitor

FindVisitor: Remove usage of try/catch for program flow.
Have SetAccessor use FormalParameterList

Added test in `test/feature/TypeAssertions/ClassParams.js` demonstrates
the #894 issue, which is fixed by this change.

I believe this is the right fix, instead of another solution proposed in #897. SetAccessor has parameterList (FormalParameterList) and therefore
annotations on SetAccessor can be transformed in the same way as
annotations on any regular function.

This change also removes the FormalParameter -> FormalParameterList
transformation in ObjectLiteralTransformer.

Fixes #894
Closes #917, #897
Merge pull request #919 from vojtajina/set-accesor-formal-parameter-list

Have SetAccessor use FormalParameterList
Rename formalParameterList and formalParamters to parameterList

This is to have more consistency in the parse tress.
Fix outputting ES6 module import
Merge pull request #921 from vojtajina/fix-output-es6-module-import

Fix outputting ES6 module import
Give traceur.js a trim.

This removes a lot of properties from the traceur object. We used
to export everything onto it and then we stopped doing that. This
removes almost everything but the properties used from src/node.
Merge pull request #920 from arv/rename-formal-parameter-list-property

Rename formalParameterList and formalParamters to parameterList
Update Promise implementation to match V8 ToT
Async Functions: Wrap await expression in resolve

Promise.cast is now Promise.resolve
Add Promise A+ tests

This adds the Promise A+ tests from domenic / promise-tests using
npm promises-aplus-tests.

The test is run using `make test-promise`
chore(Makefile): make test-promise filter more strict + update docs

Make the promise test suite filter that skips invalid tests more strict to prevent
accidental test exclusion.

Also add a better explanation of why the sloppy (non-strict mode) tests are being skipped.
Merge pull request #930 from IgorMinar/aplus-promise-fix

chore(Makefile): make test-promise filter more strict + update docs
Merge pull request #923 from arv/cleanup-traceur-properties

Give traceur.js a trim.
Destructuring: The initializer must be an object.

The following should throw a TypeError:

```js
var {x} = 1;
```

since `1` is not an Object.

This is done by wrapping the initializer in a runtime call, called
`$traceurRuntime.assertObject`

Fixes #839
Merge pull request #927 from arv/destructuring-assert-object

Destructuring: The initializer must be an object.