VFS-818 root has read and write permissions also if he is not owner

[svennissel]

If the permission of a file is 000 the user root can read and write, but not execute the file. If the permission of the file is 600 and the owner is a other user the user root can also read and write file.

[garydgregory]

-1 This PR breaks the build, run "mvn pmd:check" locally for details.

[garydgregory]

Rebase on git master as well please.