Upstream: https://secure.phabricator.com/T5750

I wonder what others think about this; I find that most of the time I search for something, I use the combination of some keyword(s) and the project for some component (or the umbrella project for multimedia), and right now that's an annoying two-step action: enter keyword(s) in quick search, arrive to search page, enter project name. If the quicksearch understood alias hashtags, that would speed things up.