Prevents files outside the root from being detected.
Fixed remove bug when files not found.

Because $stat['realpath'] was being set, the empty($stat) check was always false after that.
fix #563 (Cannot resize the treeview part)
Merge branch '2.x' into 2.1
Merge pull request #542 from Tuxion/2.x

Fixed 2 bugs. Local FS directory traversal and remove didn't notify when file not found.
optimize of #542
Merge branch '2.x' into 2.1
Merge branch '2.1' into 2.1_n