Clean coverage report as well on make clean

It doesn't make sense to not clean it anyway, plus it makes life easier
on make clean coverage
Specify source modules better for coverage tests

Just use the package name servermon instead of all the packages
themselves. This is possible now that we moved to that kind of django
hierachy but it was not before
Add 3 new hwdoc bmc commands unit tests

Get some corner cases tested
Remove unneeded check in _bmc_common.py

It was redundant anyway due to the len(args) a couple of lines above
Add unit tests for package_updates fact parsing

Also clear out some package names
Avoid a redundant check in FactValue's __unicode__

With the ForeignKeys being required no reason to check for something
that can not happen
Add updates unit tests

Use a hack to also check for the connection between hwdoc and updates
views and add some extra unit tests for plaintext reporting and hosts
without intefaces
Add hwdoc unit tests for no ajax and wrong arg

subnav and flotdata views had no unit tests for passing bad argument or
being called without the call being AJAX
Unit Test KeyValue's __unicode__ function

Add the test as it was missing
Specify a unit test for updates without origin

Not just Ubuntu or Debian but other stuff as well should be tested
Unit test for hwdoc_shutdown with force option

It was missing
Name better some facts in puppet unit tests

Or else some code does not get tested