Convert page_url to string on set

Allows any class that responds to to_s to be used
as a url path.
Implicitly wait for the page url to be displayed within some amount of time.
Reduce dependency on Capybara.default_wait_time by wrapping in locally controlled variable.
Remove test for wait_until_displayed method which was added and subsequently removed from the Page class.
Add tests for new Waiter class and implicit wait functionality for the Page.displayed? method.
Fix Waiter class definition
Do not include Waiter in the page class as Waiter is now a class.
Add configuration option to site_prism allowing use of implicit waits.
Remove depency on unmerged Waiter class.
Merge centro_production into wait_for_url_loaded
Allow capybara options to be used with element and section methods
Readme changes
More Readme changes
Document configuration for implicit waits.
Add implicit wait example.
More readme changes
More readme changes
More readme changes
replaced eager_load by lazy_load
fixed exceptions autoload