Since "too old" versions are no longer included in the generated man
page, this field is now mandatory so that it won't be forgotten and then
not included in the documentation.
Closes#7786
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
