tcl/tk: 8.6.6 -> 8.6.9

Changelog for Tcl: https://github.com/tcltk/tcl/blob/core-8-6-9/changes#L8797
Changelog for Tk: https://github.com/tcltk/tk/blob/master/changes#L7417

Tk release is actually v8.6.9.1 while Tcl is v8.6.9

pkgs/development/interpreters/tcl/8.6.nix

@@ -2,10 +2,10 @@
 
 callPackage ./generic.nix (args // rec {
   release = "8.6";
-  version = "${release}.6";
+  version = "${release}.9";
 
   src = fetchurl {
     url = "mirror://sourceforge/tcl/tcl${version}-src.tar.gz";
-    sha256 = "01zypqhy57wvh1ikk28bg733sk5kf4q568pq9v6fvcz4h6bl0rd2";
+    sha256 = "0kjzj7mkzfnb7ksxanbibibfpciyvsh5ffdlhs0bmfc75kgd435d";
   };
 })

pkgs/development/interpreters/tcl/generic.nix

@@ -33,11 +33,12 @@ stdenv.mkDerivation rec {
   postInstall = ''
     make install-private-headers
     ln -s $out/bin/tclsh${release} $out/bin/tclsh
+    ln -s $out/lib/libtcl${release}.so $out/lib/libtcl.so
   '';
 
   meta = with stdenv.lib; {
-    description = "The Tcl scription language";
-    homepage = http://www.tcl.tk/;
+    description = "The Tcl scripting language";
+    homepage = https://www.tcl.tk/;
     license = licenses.tcltk;
     platforms = platforms.all;
     maintainers = with maintainers; [ vrthra ];