Use isElementVisible instead of :visible
Change focusFirstTextInput behavior a bit

It should try first to focus a currently visible element, and only after
that try any element anywhere on the page
Fix some bugs with CoffeeScript postfix 'for' syntax
Rename window to w
Add textarea as focusable element
Minor code style
Reset scroll position if nothing found when searching
Merge pull request #305 from boris-petrov/use-is-element-visible

Random fixes and improvements