Included buildlink3.mk for libogg, as libfishsound links against it. Remove
liboggz and libsndfile from buildlink3.mk, as libfishsound does not link
against them. Added doc option, disabled by default, and handled PLIST
accordingly. Bump PKGREVISION.
Add p5-HTTP-Exception, which is required to update
p5-CGI-Application-Dispatch.

HTTP::Exception lets you throw HTTP-Errors as Exceptions.
Add p5-HTTP-Exception.