data/fonts: cleanup

* make font derivations fixed-output where applicable
 * fix dead links
 * `stdenv.lib` -> `lib` where `stdenv` is not involved
 * remove `meta.platforms = [ unix ]` and `meta.platforms = [ linux ]` because the restriction has no sense for data packages

pkgs/data/fonts/profont/default.nix

@@ -1,9 +1,9 @@
-{ stdenv, fetchzip }:
+{ lib, fetchzip }:
 
 fetchzip rec {
   name = "profont";
 
-  url = "http://tobiasjung.name/downloadfile.php?file=profont-x11.zip";
+  url = "http://web.archive.org/web/20160707013914/http://tobiasjung.name/downloadfile.php?file=profont-x11.zip";
 
   postFetch = ''
     unzip -j $downloadedFile
@@ -19,10 +19,10 @@ fetchzip rec {
 
   sha256 = "1calqmvrfv068w61f614la8mg8szas6m5i9s0lsmwjhb4qwjyxbw";
 
-  meta = with stdenv.lib; {
+  meta = with lib; {
     homepage = http://tobiasjung.name;
     description = "A monospaced font created to be a most readable font for programming";
-    maintainers = with stdenv.lib.maintainers; [ myrl ];
+    maintainers = with lib.maintainers; [ myrl ];
     license = licenses.mit;
     platforms = platforms.all;
   };