bring app to front shortcut

As it says on the title this feature would bring a configured app to the focus of the user and allow him to interact with it directly. As an example we will look at the terminal, it is often used by us programmers to recompile and debug applications we write in a different app, the text editor. As you always have to switch between the terminal, a documentation website and code, you loose quite some time, having a shortcut that always brings the Terminal(or text editor/web browser/ irc/or whatever else) to the front will enhance the desktop experience a lot.

If possible having this as a default behaviour for the terminal launch shortcut(Ctrl+Alt+T) would be perfect.

To further improve the discoverability for developers and the modularity of Pantheon, I propose storing shortcuts in a new dconf key at "org.pantheon.desktop.shortcuts". This allows third party vendors to add shortcuts easily there as well as allow other alternative Window Managers or Applications to gain that info. It might be a good idea to move the Information about the default Launcher to that place as well in order to make wingpanel and gala use the same command.