Clarify copyright ownership for code authored by Etienne Dechamps.
utils: Refactor get_name's functionality into util for global access
utils: Refactor check_id out of protocol for global access
tincctl: Use replace_name to properly replace and validate input hostnames
Remove Google from the list of copyright owners.

Google released copyright to me for my own contributions.
Fix undefined HOST_NAME_MAX on Windows.

The Windows build was broken by commit
826ad11e419db90b66b3f76a90b54df021bb39fc which introduced a dependency
on the HOST_NAME_MAX macro, which is not defined on Windows. According
to MSDN for gethostname(), the maximum length of the returned string
is 256 bytes (including the terminating null byte), so let's use that
as a fallback.