FIX: added mime types for ppt and pptx files resolved #3298
Fix Files module issue that causes the wrong items to be shown

When a user selects a different folder while the current folder’s contents are in the process of being displayed (one at a time), the items that have not yet been displayed will appear in the newly selected folder. This resolves that issue.
Adding MY_User_agent to 2.2/develop
fix ob_end_clean error
Add ogv and webm to supported mimes and file types. Closes #3317 and
revert pages admin
Checkbox fix manually applied
Validate files

https://github.com/pyrocms/pyrocms/pull/3011
Validate images too while we're at it.
Fix image field type validation.