CB-5583 WebView doesn't properly initialize when instantiated from a xib

Limit createGapView to create and position webView, configure delegate
and register with NSURLProtocol in viewDidLoad.  When `self.webView` is
created outside this class (e.g. created from Nib) then `viewDidLoad`
won't properly configure the webView's `delegate` or register with
`NSURLProtocol` properly.
Add release notes for 3.3.0
CB-5658 Fix whitelist crash when URL path has a space.
CB-5134 Add location.hash based exec() bridge.
CB-5134 Fix up bugs with new hash-based exec() bridge.