Support "curl -h --insecure" etc to output the manpage section for the
--insecure command line option in the terminal. Should be possible to
work with either long or short versions of command line options.
Closes #13990
18. Command line tool
18.1 sync
18.2 glob posts
+ 18.3 -h option
18.4 --proxycommand
18.5 UTF-8 filenames in Content-Disposition
18.6 Option to make -Z merge lined based outputs on stdout
Globbing support for -d and -F, as in 'curl -d "name=foo[0-9]" URL'.
This is easily scripted though.
+18.3 -h option
+
+ Support "curl -h --insecure" etc to output the manpage section for the
+ --insecure command line option in the terminal. Should be possible to work
+ with either long or short versions of command line options.
+
18.4 --proxycommand
Allow the user to make curl run a command and use its stdio to make requests