Test fixes

- JFactoryTest requires a database connection
- Remove failing test in JDocumentRendererTest due to other tests invalidating the expected data
- Update a couple of places overwriting the SERVER superglobal
Merge branch 'staging' of github.com:joomla/joomla-cms into staging
Improved testcases for JModel legacy classes (Fix #4807)
Removed or fixed 'risky' tests (Fix #4805)
Move legacy JModel tests to match directory structure
Mark test skipped since it's causing timeout issues
[imp] Implementing popup warning if no items are selected when marking as read or unread. Fixes #4811

Adding space before comma

Adding space before comma

Adding space before comma (had it right the first time!)
[fix] "Save as copy" button of User Group. Fixes #4778. Fixes #4798

Add return false if group could not be saved

Change name of method to fix notice errors