Adding enablePopOverlapedViewOnTap feature

Adding enablePopOverlapedViewOnTap to PSStackedViewController.

When true, overlaped views (with overlap ratio under
kPSSVOverlapMinimalValueToApplyDarkRatio) do not accept touches from
user. But, when view is tapped (via UITapGestureRecognizer), the stack
is poped to this viewController.
Container height bugfix

Sometimes, PSStackedViewController do not set the good height to a
pushed viewController … Fixed.
PSSVContainerView transparentView bugfix

Sometimes, PSSVContainerView transparentView frame is not right (it do
not take the full ContainerView bounds). Fixed.
Merge pull request #45 from Onejjy/master

Bugfixes and a new feature