Always handle rules as dicts keyed by app

In most cases, this is the useful form.  And in particular for tests
that address only one app (the most common kind), this allows much
quicker access to the relevant rules.
Merge djmitche/build-fwunit:issue10 (PR #25)
move tests to fwunit.test
add a validate.sh script
facter XML blobs out into a util module
add an integration test for SRX
add integration test for AWS
convert to using coverage directly, rather than via nosetests
test tests
Merge djmitche/build-fwunit:issue9 (PR #27)