Add options to overwrite existing Space or change Space Key

When importing spaces to Confluence, if an existing spaces shares the key/name then the import is not allowed to continue. It would be nice to have the options to either overwrite an existing Space during the import process, or have Confluence import the Space with a different key.

Currently, restoring an existing space is a two step process were we have to delete the space being importing. Automatic change of the key would also allow cloning Spaces.