Update to support Capybara 3 text normalization, current_url, and title requirements

[twalpole]

This updates the normalization of text to meet Capybara 3 requirements. It also changes current_url and title to refer to the top level browsing context when using Capybara 3+ (to more closely match the WebDriver spec) and adds frame_url and frame_title to return the current url and title of the current frame.