This checks if all command line args are documented in the help message.
Example output:
$ qa/pull-tester/check-doc.py
Args used : 144
Args documented : 133
Args undocumented: 15
set(['-uacomment', '-nodebug', '-rpcssl', '-rpccookiefile', '-checkblockindex', '-benchmark', '-help', '-version', '-h', '-checkmempool', '-mocktime', '-maptxfee', '-tor', '-socks', '-debugnet'])
Args unknown : 4
set(['-zmqpubrawblock', '-zmqpubhashtx', '-zmqpubrawtx', '-zmqpubhashblock'])
$ echo $?
15