Systems using a template tool to generate config files
might not be effective when they see the intermediate
config files we need from the host to let certain package
managers work correctly. Therefore the cleanup code in
kiwi takes care to restore from an optionally existing
template file if no other custom variant is present.
This Fixes bsc#1163978
This commit makes sure to empty RPM macros files are created during
the build. Additionally it also ensures that no needless `rm` and `mkdir`
calls are done.
Fixes#1316