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/misc/jackaudio/default.nix

@@ -5,7 +5,7 @@
 assert firewireSupport -> ffado != null;
 
 stdenv.mkDerivation rec {
-  name = "jackdbus-${version}";
+  name = "jack2-${version}";
   version = "1.9.9.5";
 
   src = fetchurl {

pkgs/misc/jackaudio/jack1.nix

@@ -4,7 +4,7 @@
 assert firewireSupport -> ffado != null;
 
 stdenv.mkDerivation rec {
-  name = "jack-${version}";
+  name = "jack1-${version}";
   version = "0.121.3";
 
   src = fetchurl {