Add support for parent elements by handling :parent selectors.
Update github pages to reflect changes in interface.

 * "Search" is no longer a button in the header
 * hrefs updated
Merge branch 'master' into child-elements
Remember watir elements until the page changes rather than allocated a new wrapped object each time the element is accessed.
Add parent element in search page model to test_github to test child elements.
Get the parent element from the page rather than the session, to fix validation issues.
Add :proc to documentation for +element+.
Allow caching to be disabled for individual elements, and add the default caching setting to the configuration.
Add support for validator blocks by defining +add_validator+.
Add a validator block to test_github to test support for it.
Check to ensure that a page's entry_url actually exists, rather than silently continue on the wrong page.
Merge branch 'cached-elems'

 * Remember watir elements until the page changes rather than allocated a new
   wrapped object each time the element is accessed.
 * Allow caching to be disabled for individual elements, and add the default
   caching setting to the configuration.
Add documentation for +:cache+ to +element+.
Remove accidental duplicate line in definition of wrap_watir.initialize.
Add support for checking the text of the alert to handle_alert.
Add an argument to handle_alert to allow it handle alerts when their presence is optional.
Bump version to 1.2.0 from 1.1.3.
Merge pull request #2 from bairyn/master

Parent elems, cached elems, block validators, handle_alert, etc.