Making the menus work in Windows Phone 7, and work better in Android / iOS

[georgestephanis]

Currently, on Windows Phone 7/7.5, the Toolbar Dropdown menus are non-functional (as there is no ontouchstart functionality in the browser) and the admin flyout menus are also entirely non-functional. This translates roughly to ... there is no way to actually log out of WordPress! (as logout is in the user dropdown menu)

iOS has some built in :hover faking code, but we should also make the admin menu flyouts more accessible and usable on Android -- where you have to touch and hold to activate the flyout/dropdown, and then slide your finger off to not trigger the actual link.

Whoops! I forgot to use wp_is_mobile() at one place.

A little JS patch that will help the admin menu and the admin bar menus operate properly in mobile devices. This way, if it's hidden, the first click will show it, and prevent the link from going anywhere. Huzzah! 20614.1.diff​

I've probably put some things in the wrong places, and I know nacin/koopersmith sounded like there was another optimization in the JS they'd like to see (koopersmith: we should bind two handlers when a menu is open. one to stop event propagation any time the #adminmenu is clicked, the other to close the menu any time the body is clicked), but I couldn't seem to wrap my head around it, so I'm tapping out to let someone else put the last bit of spit and polish on it.