Fix, properly, the disk usage stuff.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2688 71f96598-fa45-0410-b640-bcd6f8691b32
Now disk sizes are proper

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2689 71f96598-fa45-0410-b640-bcd6f8691b32
Absolute properness, sorry I'm being quite a perfectionist.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2690 71f96598-fa45-0410-b640-bcd6f8691b32