* Move install flow i18n logic to install_view.js (from options.js)
* Switch to using placeholders (instead of jQuery) for i18n messages with html.
* Switch to using moustache template instead of jQuery for i18n substitution.
// FREEBIE
Define a Whisper.View base class that automatically parses and renders
templates and attributes defined by the subclass. This saves us a good
number of lines of code as well as some marginal memory overhead, since
we are no longer saving per-instance copies of template strings.
