Make hidepip when pig configurable via a skin attribute

With the attribute hidePip="0" you are able in a skin to disable the new
hide Pip when Pig function. see

http://openpli.org/forums/topic/29948-mymetrix-2014-en-open-store/page-4
around #64

example:
<widget source="session.VideoPicture" render="Pig" position="25,98" size="440,248" backgroundColor="transparent" zPosition="2" hidePip="0"/>