HTMLBars compiler plugin for {{each .. in ..}}
HTMLBars compiler plugin for {{with .. as ..}}
Bump HTMLBars version.

Changes:

* Robust tracking of quoted and unquoted attributes.
* Refactor AST to always treat sexprs as an array.
* Add compiler plugins.

Compare view:

https://github.com/tildeio/htmlbars/compare/v0.1.11...v0.1.12
Merge pull request #9759 from emberjs/htmlbars-plugins

Use HTMLBars plugin system to transform non-standard templates.