Merge pull request #23 from KurtWagner/master

Added requestHTTPHeaders property for setting up request HTTP headers for fromUrl
Turn on edge anti-aliasing in iOS 7.0 and later:
The edges of rotated views will now be smoother.
See http://confusatory.org/post/78059850721/easy-antialiased-calayer-edges-on-ios-7-0-and-later for more info.
Merge pull request #26 from cbowns/master

Turn on edge anti-aliasing in iOS 7.0 and later
ADD: support for saving/copying image (suggested by @KurtWagner)
updating docs with new property info and project requirements
FIX: overlayAlpha value not actually being used for the background opacity
MOD: minor tweaks and improvements for rotation support
FIX: target frames improperly offset when contained within UINavigationController
FIX: reverting _originalFrame back to correct value
ADD: better support for controlling the parallax and blur effects separately
updating podspec
Merge with upstream (aka, repo that doesn't merge through but copy-pastes changes)