Rework mobile tap detection.

Now we only use hammer.js on iOS, where we can't use click events due to
the 300ms delay inherent in Safari (it waits for a double-tap, and this
can't be disabled). Everywhere else, we use click events. Fixes #88,
hopefully for real this time.

(There is some latency on Android tablets, but I'm not sure how much of
that is an event delay and how much is just lag. Either way, it
still *works*.)
Increase icon size on mobile.

Many icons, such as quote/reply/message and 'close', are hard to hit on
mobile. This should make them easier.
Merge branch 'mobile' into roost-2-init

Conflicts:
	app/coffee/endpoint.coffee
	app/coffee/view/LoginView.coffee
	app/coffee/view/MessageView.coffee
	app/coffee/view/NavBar.coffee
	app/coffee/view/SettingsPanel.coffee
	bower.json