Event: Fully clean up events in unit test

Closes gh-1685
Merge branch 'master' of https://github.com/jquery/jquery into ob
Manipulation: improve test for data-URI

Some environments do not support data-uri in "src" attribute of script element.
Mitigate it with equality assertion

Ref a467f8653a6fab2903148df80ab0ce9f5f4fd04f
Merge branch 'master' of https://github.com/jquery/jquery into ob