Add current user to ghost group

[sebgie]

To allow the user that has installed ghost to edit files within the /content folder it is necessary to add the currently active user to the ghost group. This behaviour was removed in #296 because the user needs to log out and in again to activate the new group.

Changes required:

• add user to ghost group (removed here: c499480#diff-39682f6dabedcf585eccc2dc12de55d8L42)
• change permissions for the /content folder (see Ghost folder & file permissions #294)
  • Ghost folder & file permissions #294 is important so that we are not accidentially give execution permissions to an uploaded file. This could lead to an exploit being uploaded via the file upload and executed via a vulnerability in another service running on the same machine.
• add a warning that the user needs to log out/in to acquire group permissions

[acburdine]

Closing this as it's replaced by #317