Maliit Keyboard: Update README

Still mentioned window placement bug for multi-screen setups but that code has
been removed since then.

RevBy: Jan Arne Petersen
Maliit Keyboard: Introduce new digits style for keys

RevBy: Jan Arne Petersen
Maliit Keyboard: Allow different key heights for top and bottom rows

RevBy: Jan Arne Petersen
Maliit Keyboard: Allow icons for arrow keys

RevBy: Jan Arne Petersen
Maliit Keyboard: Add xx-small, x-small key widths

RevBy: Jan Arne Petersen
Maliit Keyboard: Add activated style

Allows to present a key as active, for instance if the keyboard is in a special
mode.

RevBy: Jan Arne Petersen
Maliit Keyboard: Update layout DTD

RevBy: Jan Arne Petersen
Maliit Keyboard: Add cancel action and icon for layout menu action

Cancel action is similar to close action but it undoes the text input, too.

RevBy: Jan Arne Petersen