Bug 1024856 - [email/UI] Change hyperlink handling to explicitly trigger view activity

For links in an email, prompt as usual, but if the link starts with 'mailto:' fast path to a compose card. Otherwise, use a 'view' MozActivity.

In the process of consolidating mailto parsing, query_uri was modified to return an object with named properties instead of the more unintuitive array form. query_uri.js was also updated to pass jshint, and its unit test was updated.

Did this simpler adjustment instead of the larger suggestions around mailto links in the bug ticket so that this can easily uplift to 2.0, since there are no string changes.
I added it because app_messages only called queryURI before if url was truthy (line 56 in the old version of the file), so I felt it was safest to do the check here too since queryURI is always called now, and this guard is just a good idea in general for always allowing an object return for this function.