Document optional trace-regex in rec_control help

To clear tracing, rec_control trage-regex should be called without a regex parameter. Document in rec_control help.
Manpage: document all known options for rec_control

The rec_control manpage was missing a number of options that were mentioned in rec_control help. Rectified.
Manpage: small parameter syntax consistency

Add <> around all parameters.
Small typo fix for set-minimum-ttl
Merge pull request #1516 from sid3windr/master

Manpage and help output updates for rec_control