[update] available overlay modes enum
[add] UIView snapshot category
[add] UIImage blur category from WWDC'13
[update] overlay view
[add] blur support
Added MMHudAppearance class. From now you can setup view of hud via [MMHudAppearance appearance].
Added ability to set min hud size and const hud size
Used proper UIAppearance approach for configuring any view.
Merge pull request #1 from Yalantis/feature/appearance

Feature/appearance