Debian has a policy forbidding copies of libraries shipped with packages, instead system-installed copies should be used. Now that coverage.py includes jQuery and some jQuery plugins, the Debian package should adapt by using the system-installed jQuery (etc) instead of the coverage-shipped copies.
Coverage.py could be refactored a little to make this slightly easier.
The Debian bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=596212
The Debian policy: http://www.debian.org/doc/debian-policy/ch-source.html