LDEV-2829 updating Apache Commons IO lib(This is done because "recent versions of FileUtils (such as the 2.0.1 release) have added the use of NIO for copying files; NIO can significantly increase file-copying performance, in a large part because the NIO routines defer copying directly to the OS/filesystem rather than handle it by reading and writing bytes through the Java layer.")
LDEV-2826: Allow marking Wiki pages as removed instead of removing them completely.Clear references to unexisting pages.Fix refresh Wiki page list after removing one.
LDEV-2824: Revert changes made by previous attempt to workaround Chrome and Safari XSS detection.Replace "javascript" word in submitted Wiki pages with another token and replace it back on server side, so returning code is not identical to submitted one and XSS protection does not kick in.Clean up unnecessary methods and calls.
