fix podspec for 0.9.16

fix memory leaks

fix youknowone#140

outsource youknowone#133 to FoundationExtension

Revert default bar color for white background.

issue youknowone#115

This is confusing, because most of iOS6 apps are using navigation bar and
tab bar but they have black background color.
I need better idea to solve this problem

fix UI7NavigationBar colors by style

issue youknowone#109 related