sysutils/dtrace-toolkit: Fix manuals and wordsmith pkg-message
- Pet portfmt
- Point MANDIRS to the custom manual page directory, so that the ports framework is able to compress those manuals as well during staging.
- Rewrite the pkg-message. Most importantly, use the right man flag for accessing custom sections.
PR: 278536
Reported by: asomers
Event: Berlin Hackathon 202507