jack: change package and attr names to 'jack1' and 'jack2'

Currently, we have a 'jack' package with attrname 'jack1d' and a
'jackdbus' package with attrname 'jackaudio'. Make it consistent 'jack1'
and 'jack2' in both package name and attrname.

This aligns the naming with what can be found on the JACK homepage.

Q: what's the difference between jack1 and jack2?
A: http://trac.jackaudio.org/wiki/Q_differenc_jack1_jack2

pkgs/applications/audio/lash/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, alsaLib, gtk, jackaudio, libuuid, libxml2
+{ stdenv, fetchurl, alsaLib, gtk, jack2, libuuid, libxml2
 , makeWrapper, pkgconfig, readline }:
 
 assert libuuid != null;
@@ -15,7 +15,7 @@ stdenv.mkDerivation  rec {
   # http://permalink.gmane.org/gmane.linux.redhat.fedora.extras.cvs/822346
   patches = [ ./socket.patch ./gcc-47.patch ];
 
-  buildInputs = [ alsaLib gtk jackaudio libuuid libxml2 makeWrapper
+  buildInputs = [ alsaLib gtk jack2 libuuid libxml2 makeWrapper
     pkgconfig readline ];
 
   postInstall = ''