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.