vnode/vfs and vnode/vfs operations removal

XFS has long carried around some baggage left from IRIX, and the vnodes and vfs objects aswell as the associated operation vectors re probably the worst, both in their impact in size aswell as in maintainability of the code. This patchset removes all this cruft, and allow at the same time to do a more clear split between the generic and the linux-specific parts of the current XFS codebase.

The patchseries allows for some quite nice reduction in size of both the source an binary code:

 113 files changed, 2114 insertions(+), 4002 deletions(-)

-rw-r--r-- 1 hch hch 9394858 2007-08-23 19:43 xfs.ko.new -rw-r--r-- 1 hch hch 9660812 2007-08-23 19:13 xfs.ko.old