Add .execenv files to set QT_NUM_SHEPHERDS=2 and update .lm-numa.good files

The number of communications depends on the number of shepherds when using the
numa locale model, so force the number of qthreads shepherds to 2.  Update
the .lm-numa.good files to match the comm counts for two shepherds.
Merge pull request #752 from daviditen/numaCommCountUpdates

Add .execenv files to set QT_NUM_SHEPHERDS=2 and update .lm-numa.good files
[reviewed by ronawho]

The number of communications depends on the number of shepherds when using the
numa locale model, so force the number of qthreads shepherds to 2. Update
the .lm-numa.good files to match the comm counts for two shepherds.