CardView: enable stacked cards by default and manage parenting of card windows in same stack

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
CardView: when adding a parented card, put it in front of the group and set it as the active card

Signed-off-by: Christophe Chapuis <chris.chapuis@gmail.com>
Merge pull request #156 from webOS-ports/tofe/fixes

CardView: enable stacked cards by default and manage parenting of card w...