Expose permission options for registry uploads
As stated in Bug# 1982, when adding data objects to a metadata upload, the registry skins should expose a permissions. Currently, all files default to being private to the data package owner, but should instead provide a radio button like:
[x] publically available [ ] private
This option could either be per-file, or a single option for all data objects associated with the metadata object. In special cases such as the NCEAS registry, we may want an additional option such as 'Group available' which is determined by group identities stored in LDAP. This would require further integration of the Admin DB LDAP and the registry code.