Revert "Support other platforms"
Revert "Support other platforms"

This reverts commit a42c1198965848f0661dd2d4ccbd9aa33f45e81d.

ninjaprox/NVActivityIndicatorView,waterskier2007/NVActivityIndicatorView,waterskier2007/NVActivityIndicatorView,ninjaprox/NVActivityIndicatorView,ninjaprox/NVActivityIndicatorView,ninjaprox/NVActivityIndicatorView