Mark some packages as low priority and disambiguate some others

pkgs/applications/networking/browsers/netsurf/libnsgif.nix

@@ -1,6 +1,6 @@
 args: with args;
 stdenv.mkDerivation {
-  name = "libnsbmp-0.0.1";
+  name = "libnsgif-0.0.1";
 
   src = fetchurl {
     url = http://www.netsurf-browser.org/projects/releases/libnsgif-0.0.1-src.tar.gz;
@@ -10,7 +10,7 @@ stdenv.mkDerivation {
   installPhase = "make PREFIX=$out install";
   buildInputs = [];
 
-  meta = { 
+  meta = {
     description = "Libnsbmp is a decoding library for gif image file formats"; # used by netsurf
     homepage = http://www.netsurf-browser.org/projects/libnsgif/;
     license = "MIT";