Click elements with native events
Raise error when elements are unclickable
Raise error when iframe elements are unclickable
Capybara should retry when ClickFailed is raised
JavaScript error handling
Serialize errors as JSON
Raise Capybara.ClickFailed on click test failure

Prevents Node#set from succeeding when click test fails.
Return element and position for ClickFailed error
Extract error initialization to JsonError module
Rename Command::emitFinished to finish
Update NEWS for HEAD