added unbound to external deps

external/unbound/contrib/unbound_cache.cmd

@@ -0,0 +1,65 @@
+@echo off
+rem --------------------------------------------------------------
+rem -- DNS cache save/load script
+rem --
+rem -- Version 1.0
+rem -- By Yuri Voinov (c) 2014
+rem --------------------------------------------------------------
+
+rem Variables
+set prefix="C:\Program Files (x86)"
+set program_path=%prefix%\Unbound
+set uc=%program_path%\unbound-control.exe
+set fname="unbound_cache.dmp"
+
+rem Check Unbound installed
+if exist %uc% goto start
+echo Unbound control not found. Exiting...
+exit 1
+
+:start
+
+set arg=%1
+
+if /I "%arg%" == "-h" goto help
+
+if "%arg%" == "" (
+echo Loading cache from %program_path%\%fname%
+type %program_path%\%fname%|%uc% load_cache
+goto end
+)
+
+if /I "%arg%" == "-s" (
+echo Saving cache to %program_path%\%fname%
+%uc% dump_cache>%program_path%\%fname%
+echo ok
+goto end
+)
+
+if /I "%arg%" == "-l" (
+echo Loading cache from %program_path%\%fname%
+type %program_path%\%fname%|%uc% load_cache
+goto end
+)
+
+if /I "%arg%" == "-r" (
+echo Saving cache to %program_path%\%fname%
+%uc% dump_cache>%program_path%\%fname%
+echo ok
+echo Loading cache from %program_path%\%fname%
+type %program_path%\%fname%|%uc% load_cache
+goto end
+)
+
+:help
+echo Usage: unbound_cache.cmd [-s] or [-l] or [-r] or [-h]
+echo.
+echo l - Load - default mode. Warming up Unbound DNS cache from saved file. cache-ttl must be high value.
+echo s - Save - save Unbound DNS cache contents to plain file with domain names.
+echo r - Reload - reloadind new cache entries and refresh existing cache
+echo h - this screen.
+echo Note: Run without any arguments will be in default mode.
+echo       Also, unbound-control must be configured.
+exit 1
+
+:end