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/development/tools/sauce-connect/default.nix

@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
 
   meta = {
     description = "A secure tunneling app for executing tests securely when testing behind firewalls";
-    license = "unfree";
+    license = with licenses; unfree;
     homepage = https://docs.saucelabs.com/reference/sauce-connect/;
     maintainers = with maintainers; [offline];
     platforms = with platforms; platforms.linux;