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/development/libraries/git2/0.21.nix

@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ zlib libssh2 openssl http-parser ];
 
   meta = {
-    description = "the Git linkable library";
+    description = "The Git linkable library";
     homepage = http://libgit2.github.com/;
     license = stdenv.lib.licenses.gpl2;
     platforms = with stdenv.lib.platforms; all;

pkgs/development/libraries/git2/default.nix

@@ -16,7 +16,7 @@ stdenv.mkDerivation (rec {
   buildInputs = [ zlib libssh2 openssl http-parser ];
 
   meta = {
-    description = "the Git linkable library";
+    description = "The Git linkable library";
     homepage = http://libgit2.github.com/;
     license = stdenv.lib.licenses.gpl2;
     platforms = with stdenv.lib.platforms; all;