Add option for the default property appearance.

[seanrockster]

It would very handy if there was a config option or something so that I can select the property appearance globally. E.g. if I want to use label above option throughout the site and only use label to the left in a few cases where it makes sense, i don't have to change it for the majority of properties, rather just change it for the few where i do want label left instead of label above. Also, it tends to get skipped and then the backoffice can look a bit messy with different label options (left and above).