CB-5595 Add toolbarposition=top option.

The position of the toolbar is now configurable, it can be specified on
the caller's side. The possible values are top and bottom and the key
for the setting is toolbarposition. Also extended the logging of the web
view's load errors, it now logs the error code too, not just the
localized description of the error that occured. Added the
browserOptions to the init method's parameters in order to make it
conveniently accessible from the ViewController.
CB-5595 Fixed the positioning and autoresizing for certain rotation scenarios.

The autoresizing masks are applied conditonally based on the
browserOptions.toolbarposition flag to ensure that the toolbar is in
its correct place. Also added a utility function to query the
necessary offset for the status bar: the function takes care of the iOS
version and orientation caused differences without hardcoding the value
as 20 pixels.
CB-5595 Rename "toolbarbarpostion" -> "toolbarposition"
CB-5594 Add disallowoverscroll option.

Similar to the main cordova webview