Add code to handle the common Arch compare case.

This could certainly be more generic, but given the
small set of arches we care about, this should be
sufficient for now.
Count content with empty arch lists as compatible
add toString for ProductContent for debug logging
remove generic awesomeos content repo for arch test cases
handle the "ALL" arch for inherited content arches
Check Product arch if content does not have arch

ie, let the content inherit the product arches if
it doesnt specify arches directly.
Add 'ALL' arch type to our Arch table
checkstyle cleanups