[keyboard] adds code for loading keyboard layouts
[keyboard] adds keyboardlayouts.xml
[keyboard] settings for keyboard layouts
[keyboard] changes to GUIDialogKeyboardGeneric for layouts
[gui] bump skin version to 5.3.0, remove backward compatibility code in the keyboard dialog as changes are no longer BW compat. Version 5.0.0 skins will still load, but should be updated to 5.3.0 in preparation for Helix
[confluence] adds support for keyboard layouts to confluence.