change Fauxton username variable in testing
Input field in clone doc modal full width

Just a small style fix. There wasn't enough space so the input field
in the modal now spans 100%.
New waitForAttribute nightwatch helper

This test allows us to not just wait for an element, but for an
element attribute containing a certain value. This can be helpful in a
number of scenarios, like when a JS event changes the content of a page
but the DOM structure remains largely the same (e.g. a form).