GUI-1300: Move sharing panel to "Advanced" accordion 

...and remove "Enable versioning" option in accordion on Create Bucket page.

Fixes https://eucalyptus.atlassian.net/browse/GUI-1300

Note that removing the Enable versioning option is within the scope of GUI-1315 and was done here to avoid potential merge conflicts.  The remaining work for GUI-1315 will be completed in a separate pull request.