echo SYSSYSR1 | sed 's/SYS.+/sysr1/'
was producing SYSsysr1 instead of sysr1.
Bug was introduced during overflow cleanup earlier this year.
Also bring regexec.c and rregexec.c into sync again.
Also allocate large enough lists in the regexec2/rregexec2 case.
Just like outputthread can have processed the message
but not yet called msgput, the same is true of the
connoutthread, so we cannot check c->nmsg until
after the connoutthread has shut down gracefully.