Delete klkt

Because klkt is no longer maintained, delete it from the source tree.

inc/lektor/internal/config.def

@@ -102,12 +102,10 @@ comment("               listening for clients. All the modules needed (player, r
 comment("               has been created.")
 
 comment("The available hooks are the followings:")
-comment(" - none:            Nothing, the hook is ignored")
-comment(" - launch_ext_klkt: Launch klkt, note that it will be automatically killed")
-comment("                    when lektord exits")
-comment(" - launch_caching:  Launch caching for the database. The mtime and the duration")
-comment("                    of the karas are cached, this is used to speedup the ")
-comment("                    update process")
+comment(" - none:                    Nothing, the hook is ignored")
+comment(" - launch_caching:          Launch caching for the database. The mtime and the")
+comment("                            duration of the karas are cached, this is used to")
+comment("                            speedup the update process")
 comment(" - database_upgrade_scheme: Upgrade the database scheme, usefull at launch time.")
 comment("                            It should be the first one to avoid any problem")
 comment("                            (lektord may crash if it's not the first element...)")