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.
Our regexp for this is the case-insensitive `/^mailto:/i` so to avoid weirdness I think it'd be best to just use that exactly.  (And I understand using it inline is performant given how SpiderMonkey caches stuff, although you can put it in a constant-ish thing if you want, etc.)