txt2man: new package

txt2man converts flat ASCII text to man page format. (Solfege, which is
added in the next commit, needs this.)

pkgs/tools/misc/txt2man/default.nix

···
+{ stdenv, fetchurl }:
+
+stdenv.mkDerivation rec {
+  name = "txt2man-1.5.6";
+
+  src = fetchurl {
+    url = "http://mvertes.free.fr/download/${name}.tar.gz";
+    sha256 = "0ammlb4pwc4ya1kc9791vjl830074zrpfcmzc18lkcqczp2jaj4q";
+  };
+
+  preConfigure = ''
+    makeFlags=prefix="$out"
+  '';
+
+  meta = { 
+    description = "Convert flat ASCII text to man page format";
+    homepage = http://mvertes.free.fr/;
+    license = stdenv.lib.licenses.gpl2;
+    platforms = stdenv.lib.platforms.linux;
+    maintainers = with stdenv.lib.maintainers; [ bjornfor ];
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   ttf2pt1 = callPackage ../tools/misc/ttf2pt1 { };
 
+  txt2man = callPackage ../tools/misc/txt2man { };
+
   ucl = callPackage ../development/libraries/ucl { };
 
   udftools = callPackage ../tools/filesystems/udftools {};