BUG: skeleton.c handler example should mention it requires binary format + add doc for code format = string mode

[sgpinkus]

Please update text in the wiki surrounding the skeleton.c example audispd listener here, to mention it only works correctly plugin conf format set to "binary". The default value is "string".

A note on how data is passed to listeners when format is "string" would also be helpful here. Specifically:

• assert no header is sent
• records are newline terminated, so i.e. it's essentially equivalent to tailing the audit.log.
• clarify guarantees or lack there of about how multi record (line) events are delivered - are they guaranteed to be contiguous? Are they always available all at once without blocking?

[pcmoore]

Let's bring this to @stevegrubb's attention.

[stevegrubb]

With the audit-3.0 design, there is no separate audispd. Everything now is a plugin to auditd. With that change, skeleton.c has been dropped from the codebase. This happened over a year ago.