Treat consecutive lines that start with a space to be "examples". They
are output enclosed by .nf and .fi
Updated form.d to use this new fanciness
Closes#8016
The file format for each option now features a "Example:" header that
can provide one or more examples that get rendered appropriately in the
output. All options MUST have at least one example or gen.pl complains
at build-time.
This fix also does a few other minor format and consistency cleanups.
Closes#7654