Added a sleep method in the Cycles class to busy wait
for a given number of microseconds. One should almost
always use this method as opposed to calling usleep
in performance benchmarks. The documentation for the
function describes the problem with using usleep.
Changing default value of totalMasterMemory server option.
Object Finder now caches meta-data for each table separately.
Modified documentation to reflect support for only single indexlet. Index key now
spans all possible range of keys, excluding keys beginning with ascii char '127'(DEL).
Added index scalability experiment to cluter perf.
Added two indexing benchmarks to ClusterPerf

i) The first experiment measures basic indexing performance
   (writes, overWrites and lookup+indexedReads)
ii) The second experiment measures how overwrite times vary
    as the number of indexes/object is varied.

For both the experiments, the min, max, avg and median
are computed and printed.
Merge branch 'master' of ssh://fiz.stanford.edu/git/ramcloud

Conflicts:
	scripts/clusterperf.py
	src/ClusterPerf.cc
Minor cosmetic change to clusterperf