Changing the "popoverVisible" @property to match the UIPopoverController API.
adding popover completion block
Merge pull request #65 from barz/visibility-api

Changing the "popoverVisible" @property to match the UIPopoverController API
Merge pull request #66 from barz/completion-block

adding popover completion block
fix issue #64
fix issue #69
Merge branch 'master' of https://github.com/nicolaschengdev/WYPopoverController into merge

Conflicts:
	WYPopoverController/WYPopoverController.h
	WYPopoverController/WYPopoverController.m
Merge branch 'merge' into barz-master