Added Aspec property to ImageGallery
Merge pull request #301 from Applifting/master

Added Separator control for Android and iOS
Update beta91 close #293
Backpress handling updated

Made the delegate func async. Added override for OnBackPressed Android
Activity. Will update the sample with an example usage page a bit later.
Added Separator renderer for WP8

No orientation support yet. Renders the sample page.
Reverted adding the aspect to Image Gallery
Merge commit '9a78fc0d89c09892a523282b31373dc9c5d15b94'