Use common licence attributes from lib/licenses.nix

Many (less easily automatically converted) old-style strings
remain.

Where there was any possible ambiguity about the exact version or
variant intended, nothing was changed. IANAL, nor a search robot.

Use `with stdenv.lib` wherever it makes sense.

pkgs/tools/networking/nss-pam-ldapd/default.nix

@@ -26,9 +26,9 @@ stdenv.mkDerivation rec {
     wrapProgram $out/sbin/nslcd --prefix LD_LIBRARY_PATH ":" $out/lib
   '';
 
-  meta = {
+  meta = with stdenv.lib; {
     description = "LDAP identity and authentication for NSS/PAM";
     homepage = http://arthurdejong.org/nss-pam-ldapd/;
-    license = [ "GPLv21" ];
+    license = with licenses; [ lgpl21 ];
   };
 }