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.
Let's add a comment here that says this is okay because queryURI explicitly only populates the listed set of properties and so an attacker can't put anything in the object that we weren't already expecting.