View source for Mobile/Projects/Helper widgets for error pages

== Tracking ==
<bugzilla>
{
    "bug_id": "940453,482874",
    "resolution": "---",
    "include_fields": "id, summary, status, assigned_to, last_change_time",
    "order": "bug_id"
}
</bugzilla>

== Goals ==
Create a widget-system for our error pages that will allow us to easily add hints or other information to help users understand and fix whatever problem they've encountered.

We will need an initial set of widgets to cover our existing error states ([http://mxr.mozilla.org/mozilla-central/source/mobile/locales/en-US/overrides/netError.dtd reference]), and then we'll be able to build additional widgets in the future to deal with new things as they arise.

== User stories & use cases ==
We will need widgets to deal with each of the error states currently handled by Firefox, listed in the [http://mxr.mozilla.org/mozilla-central/source/mobile/locales/en-US/overrides/netError.dtd netError.dtd].

== UX design ==
* TBD

== Justification ==
* User value in that it will be significantly easier to ship more and better error-related information, so users can better understand what went wrong and have some idea of how to fix it.

== References and other info ==
* TBD

== Quality criteria ==
* No user-perceptible performance degradation
* All goals are met
* All "must have" user stories/use cases are implemented & tested