Estree compatibility as plugin (#277)

* Initial estree support for ClassMethod

* Handle literals for estree

* Fix regex

* correct output of regexp and regenerate test

* Add tests for validation stuff with estree plugin

* Parse Properties correctly

This also refactors how babylon parses obj properties in general
so that this logic can be more easily extended.

* Run all throws-tests a second time with estree plugin

* Fix all throw tests

* Remove rebase conflict

* Correctly set kind

This ensures state.inMethod gets propagated correctly

* Add computed: false to methods with ident async

* Implement directive field on Directives

* Test invalid directives

* more tests

test/fixtures/estree/object-method/basic/actual.js

@@ -0,0 +1,3 @@
+var bar = {
+  foo() {}
+};