Updates for pdsh-2.31

doc: Update documentation for -g

genders: Update error message for use of -A/-a with -g

testsuite: genders: Add Py Watson's genders test combo to testsuite

genders: Speed up genders_filter

testsuite: genders: Add test for slowness when -g used to filter -w

genders: Fix redundant traversal of wcoll with -g

testsuite: Add timing test for genders

testsuite: Add test for -P with -w

slurm: Allow mixed use of -P, -w, and -j options

Updates for pdsh-2.30

Update hostlist to latest version from upstream

testsuite: Add test genders -X excludes more hosts than expected

testsuite: fix test for mrsh support on localhost

Updates for pdsh-2.29