don't define Zaptel features as libraries, they aren't, and we don't want...

don't define Zaptel features as libraries, they aren't, and we don't want '--with-zaptel-<foo>' configure options for them
also some minor cleanups


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@109166 65c4cc65-6c06-0410-ace0-fbb531ad65f3