WindowManager: improve the scaling of the keyboard

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
WindowManager: set opacity=0.99 for the overlay window, to force the alpha channel to be taken into account

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Merge pull request #41 from webOS-ports/tofe/work

Tofe/work