Add public check-out flag on attachments to notify users

Users who are communally editing page attachments are not notified that the file is being updated by other users. The simplest way to address this issue is to add a checkout field to each file on the attachments tab.

Example:

Name Size Creator Date Being Edited Comment
Image.jpg 0.5 kb Anonymous Sep 25, 2006 No Test Image

Name Size Creator Date Being Edited Comment
Image.jpg 0.5 kb Anonymous Sep 25, 2006 [John User] Test Image

• Each attachment has a checkout username and checkout timestamp associated with it.
• Each attachment has the options to Edit, Remove or Check Out. If a user has checked out a file, the link becomes Check In for that user only.
• The user link is to their email address eg [John User|john@company.com]. Mousing over a user shows the date the checkout was performed eg Since 17 Dec 06.
• Checkouts are automatically removed with a user uploads the file or clicks Check In.
• Checkout don't expire and are removed by a user checking out a file then checking it back in.
• There is no file locking.
• Only one user is listed as having a file checked out, so checking a file out when another user has checked it out overwrites the owner.