Rename XXX_Fingerprint to XXX_CertFp
Fix spelling
Add Client_HasFlag() to check if a client has certain flag
Change cloaked hostname to be malloc'd on demand

This shaves a few bytes when cloaked hostnames are not used and
restricts the cloakhost announcement iif there is something to
send.
More spelling fixes

Remove superflous comments, mostly in German. Fix spelling and
use american variants for consistency.