Captialize meta.description of all packages

In line with the Nixpkgs manual.

A mechanical change, done with this command:

  find pkgs -name "*.nix" | \
      while read f; do \
          sed -e 's/description\s*=\s*"\([a-z]\)/description = "\u\1/' -i "$f"; \
      done

I manually skipped some:

* Descriptions starting with an abbreviation, a user name or package name
* Frequently generated expressions (haskell-packages.nix)

pkgs/tools/misc/proxytunnel/default.nix

@@ -13,7 +13,7 @@ stdenv.mkDerivation {
   installPhase = ''make DESTDIR="$out" PREFIX="" install'';
 
   meta = {
-    description = "program that connects stdin and stdout to a server somewhere on the network, through a standard HTTPS proxy";
+    description = "Program that connects stdin and stdout to a server somewhere on the network, through a standard HTTPS proxy";
     homepage = http://proxytunnel.sourceforge.net/download.php;
     license = stdenv.lib.licenses.gpl2;
   };