[Ready for Merge] Implemented a FlipView control.

[AzureKitsune]

Implemented a simple FlipView control based on the one in Windows Store Apps (Windows 8/RT Metro Apps).

Based on the Selector control (like it's W.S.A. counterpart) and uses the TransitioningContentControl at it's core.

• Implement base control.
• Implement a banner.
• Change arrows.
• Implement any feedback provided by others: (See below)
• Don't show banner if BannerText is null. Invalid because FlipView is trying to emulate it's W8 counterpart.
• The appropriate control button disables if it cannot be used depending on SelectedIndex.
• Further emulate Windows 8 behavior by keeping Banner shown as long as IsBannerEnabled is true.

[AzureKitsune]

I have taken the liberty to implement a banner which slides up from the bottom of the control to display text. The BannerText property is bindable.

[shiftkey]

A few little things:

When at the start of the list, the left button should not be visible. Same thing with the end and the right button.

Banner message:

• should it show up on start and every transition? I like how Instagram does their banner message - it fades in when you hover over it.
• should the banner message be visible if it isn't set?

[shiftkey]

Put the demo on the second row so you can get some space for the banner text (currently partially cut off)

And make the banner enabled by default

[AzureKitsune]

Banner is now enabled by default. If I put the FlipView, it would be the same result unless I change the RowHeight. I made it span 2 rows instead, for now.

[AzureKitsune]

More bugs have been discovered. This may take longer than I thought.

[AzureKitsune]

Ready for merging.

[damced]

In Flip, focus show like a gray border over the control when mouse is over a child control. How can hide that border?