Fix __IPHONE_OS_VERSION_{MIN_REQUIRED,MAX_ALLOWED} mixup in SSWebViewController

Signed-off-by: Alexsander Akers <a2@pandamonia.us>
Merge pull request #173 from a2/master

Fix __IPHONE_OS_VERSION_{MIN_REQUIRED,MAX_ALLOWED} mixup in SSWebViewController
Eliminate duplicate present / dismiss messages when handling modal view controllers.
Adopt latest podspec changes (compatibility to CocoaPods 0.17.x).
Merge pull request #177 from plu/master

Adopt latest podspec changes (compatibility to CocoaPods 0.17.x).