Most of the core plugins were already hidden, this hides
chat, styleguide, and checklist to avoid potential confusion
for end users.
Also removes respond_to? :hide_plugin, since that API has been
in place for a while now.
* Remove some `.es6` from comments where it does not matter
* Use a post processor for transpilation
This will allow us to eventually use the directory structure to
transpile rather than the extension.
* FIX: Some errors and clean up in confirm-new-email
It would throw an error if the webauthn element wasn't present.
Also I changed things so that no-module is not explicitly
referenced.
* Remove `no-module`
Instead we allow a magic comment: `// discourse-skip-module` to prevent
the asset pipeline from creating a module.
* DEV: Enable babel transpilation based on directory
If it's in `app/assets/javascripts/dicourse` it will be transpiled
even without the `.es6` extension.
* REFACTOR: Remove Tilt/ES6ModuleTranspiler
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
