Fix removeClass() with no arguments not removing all classes

[gmcnaughton]

Fixes #2 (calling removeClass() with no arguments does not remove all classes).

jQuery's behavior changed somewhere between 1.4.4 and 1.11.3; the 'empty' test case works against 1.4.4 but not 1.11.3 or 2.1.4. Changing the fallback case to pass along the original arguments fixes the issue.