GTK: dfinput added emulator key (hotkey) mapping to keyboard or controller. Existing hotkeys are hard coded like F1 for savestate, but now it can have an alias hotkey on keyboard s button for example. These can be configured from dfinput dialog. Also added support for fastforward key (tilde / section key). Currently only dfxvideo supports it by full extent. Hopefully someone can merge these changes to Windows build.

git-svn-id: https://pcsxr.svn.codeplex.com/svn/pcsxr@84102 e17a0e51-4ae3-4d35-97c3-1a29b211df97