Working Cleaner and Various Updates

[Pradeep P. <pp...@ee...>]

Hi,
    I have checked in a functional cleaner into the main trunk. The 
cleaner is connected to the kernel side using ioctls, and a lot of 
functionality needed by the cleaner is added to the kernel.
    I have tested only the main flow, and the amount of functionality 
added to the kernel might have made the kernel module unstable.
    If you want to try the cleaner, run it with the -q option to run it 
only once.

Detailed Changelog below
*) lfsprogs
	- segsum, segusage entries added for the first few inodes
	- i_ino added, needed by the cleaner to identify the inode to
           which an inode block belongs.
*) Cleaner
	- cost-benefit algorithm working
	- finfo, seguse entries read and updated correctly.
	- reading, and writing through ioctls is functional
*) Kernel-side
	- seguse.c added (seguse table functionality)
	- segsum.c added (segment summary, finfo and friends
           functionality)
	- ioctl.c added (ioctl functionality)

-- 
Pradeep Padala
http://ppadala.blogspot.com