Merge branches 'bigrtm.2012.07.04a', 'doctorture.2012.07.02a',...

Merge branches 'bigrtm.2012.07.04a', 'doctorture.2012.07.02a', 'fixes.2012.07.06a' and 'fnh.2012.07.02a' into HEAD

bigrtm: First steps towards getting RCU out of the way of
	tens-of-microseconds real-time response on systems compiled
	with NR_CPUS=4096.  Also cleanups for and increased concurrency
	of rcu_barrier() family of primitives.
doctorture: rcutorture and documentation improvements.
fixes:  Miscellaneous fixes.
fnh: RCU_FAST_NO_HZ fixes and improvements.