Dock navigation: if it appear on hover, close it on hover after a timeout

The new navigation "Dock" in Moodle 2.0 adds important flexibility for the user to control how much stuff they have on their screen.

The current issue with the menu is that it appears on hover but users need to close it by clicking outside it.

It opens very effortlessly, but this also makes it easy to activate them accidentally while hovering around.

For consistency and a decrease in annoyances, make it easier to close the navigation menus opened

• If the menu is opened on hover, it needs to close on hover out after a timeout of 1-3 seconds.
• Add an explicit X icon at the top right corner of each menu to allow users to get rid of the annoyance immediately