Set hostname as computer node name in audit logs.

[adelton]

Description:

• Set hostname as computer node name in audit logs.

Rationale:

• If option name_format is left at its default value of none, audit events from different computers may be hard to distinguish.

[jan-cerny]

@adelton The patch looks good to me, but please resolve the conflicting files.

[adelton]

Please start with #4695 -- that one has already been rebased, and since the other pull requests conflict with each other, we really need to do it in the original order. I'll rebase once #4695 is in.

[jan-cerny]

@adelton OK, I'll review #4695 first.

[adelton]

Thanks. Rebased on master -> 59c9e7e.