Release Notes: Net builds now support the use of a cluster's mpiexec systems for job launch, via charmrun's ++mpiexec option. CPU affinity can be set more easily using +pemap and +commap options instead of the older +coremap. Projection logs can be spread across multiple directories, speeding up output when dealing with thousands of cores. +trace-subdirs N will divide log files evenly among N subdirectories of the trace root, named PROGNAME.projdir.K. Many other changes were made.