ext4 improvements [LK 3.2]

http://kernelnewbies.org/Linux_3.2#head-020618faa379902cf1a212e2d6c48230104e426e
Revert "Proportional Rate Reduction for TCP."

I do not think we need it.

https://github.com/TeamCanjica/android_kernel_samsung_u8500/commit/461067b15abdafd14d9fb4120f1e21244a9c7f12
(see comments)
https://github.com/TeamCanjica/android_kernel_samsung_u8500/commit/f4eed8b37adcc705c8bc31269e809e390724d07f

I trust cocafe :D