Schedule Content for XF 2.x 2.2.0

Notable changes:

• Fixed input change content owner still show to users did not have permission
• Fixed issue schedule do not save in some cases.

Notable changes:

• Fixed schedule list navigation show to user who have not permission to view.

Notable changes:

• Fixed error call undefined method canEdit
• Added new page to listing all schedules

Notable Changes:

• Rewrite this add-on.

Notable changes:

• Fixed schedule inputs still show to users did not have permissions.

Remove default schedule date on new thread form

Fixed invalid date.

Notable changes:

• Added cron to publishing contents
• Added action while manual stop scheduling.
• Improvement add-on

Added permission to restrict change owner content.