Fixed help output for scripts/run_benchs.rb for Hector.
Merge branch 'master' of https://github.com/poconbhui/Towards-Exascale-MD
Fixed stupid mistake in benchmark.f90. Timing is now estimated first and process 0 determines in advance how many reps the benchmark should perform. Added benchmark flags to the distributions to allow MPI to be switched on and off and calculations to be switched on and off.