fs/dcache.c: adaptive vfs_cache_pressure on suspend / resume [dorimanx]

Low vfs_cache pressure values save battery while idle, while
a low value also causes stutter with longer up times.
Big thanks to @temasek for sharing
adaptive cache_pressure fix
Enable bswap by default
block: introduce the BFQ-v7r5 I/O sched for 3.4
block, bfq: add Early Queue Merge (EQM) to BFQ-v7r5 for 3.4.0
Makefile change
configdump
interactive tweak
config dump
BFS attempt