Constructs a roff man page based on the funopt usage.
Program name, as it should appear in the header, synopsis etc. If not specified, the identifier name of FUN is used.
Long description for the DESCRIPTION section. If not specified, we either use the function string UDA, or omit the section entirely.
Short description for the NAME section. If not specified, generated from the function string UDA.
Additional sections (BUGS, AUTHORS) to add at the end.