Footer style updates from Vibha

Change-Id: I02aac1dbba6d214873e3a2cc6e985bff1464890c
Removed toc image cruft. Much faster on old devices.

Change-Id: I8ddd4e465665fd7f60d00d084ded5557f3b84a48
Merge "Footer style updates from Vibha"
Pull to refresh refactor

Refactored pull-to-refresh logic out of WebViewController into
PullToRefreshViewController, which can be subclassed and reused.

Child class needs to override methods to get the scroll view,
return appropriate strings for the label, and perform action
on completion.

Note that this sets the scroll view's delegate to the view controller,
so if doing additional scroll view delegate stuff you may need to
call a parent method to avoid losing the pull to refresh behavior.

Change-Id: I7c4a69f5598f9bd359567074992ce4253d4df6ee