Merge remote-tracking branch 'origin/v320a_dev'

v3.20a has been in development for several months now and appears stable enough
to merge to master.

Sysops running v3.19 or earlier *must* run 'jsexec update' to get their config
files (ctrl/*.cnf) converted to *.ini and their user base (data/user/user.dat)
converted to user.tab.