Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r234636 and r234655:
Improve support for USB packet filtering also when reading dumps, and
allow filtered data to be dumped to a binary file.

Add missing and probably also mandatory -h option.

MFC r231835:
Add support for filtering USB traces using the BPF functionality.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Minor wording adjustments to usbdump(8).

PR: docs/157317
Submitted by: Warren Block (wblock at wonkity dot com)
Reviewed by: hps@
MFC after: 5 days

[mdoc] Fixed .Dt call.

Documents OUTPUT formats. While I'm here cleans up styles and words.

Reviewed by: brueffer@

Adds usbdump(8) tool that currently it only supports the very basic
feature set. It's not connected to the build yet.

Reviewed by: hps