Prepared ProgressIndicator for overwriting in iOS.
Merge pull request #51 from kfa/progressindicator_prepare_ios

Prepared ProgressIndicator for overwriting in iOS.
Added theming for ProgressIndicator in iOS.
Merge pull request #52 from kfa/ios_appearance_indicator

Added theming for ProgressIndicator in iOS.
Updated tabbar to use Carousel.
Update TabPanel implementation to use Carousel.
Merge pull request #53 from dankurka/update_tabpanel

Update tabpanel