Remove general assumption in get_packages()

get_packages() always included 'general' as a default 'service' file.
Remove this assumption and add it explicitly to the primary package
installation call.  This allows get_package() to be used in other places
where 'general' is not desired to be included.

Change-Id: I1eed4386d073d6ae9534aedae32654208c6662e8
Merge branch 'config-local' into dt-test
Merge branch 'hypervisor-xenserver' into dt-test
Merge branch 'no-root' into dt-test
Merge branch 'fix-get-packages' into dt-test
Merge branch 'ldap-ad' into dt-test