Add support for gettext message catalogs.

tools/xgettext.bat

@@ -0,0 +1,33 @@
+@echo off
+setlocal
+
+set me=%~n0
+
+rem # Uncomment the following line if gettext is not in your PATH.
+rem # Value must be absolute and end in a backslash.
+rem set gtprefix=C:\path\to\gettext\bin\
+
+if "%1" == "" (
+	echo Usage: %me% FILE... 1>&2
+	exit 1
+)
+
+set xgettext=%gtprefix%xgettext.exe
+set msgmerge=%gtprefix%msgmerge.exe
+
+md locale > nul 2>&1
+echo Generating template... 1>&2
+echo %xgettext% --from-code=UTF-8 -kS -kNS:1,2 -k_ -o locale/template.pot %*
+%xgettext% --from-code=UTF-8 -kS -kNS:1,2 -k_ -o locale/template.pot %*
+if %ERRORLEVEL% neq 0 goto done
+
+cd locale
+
+for %%f in (*.po) do (
+	echo Updating %%f... 1>&2
+	%msgmerge% --update %%f template.pot
+)
+
+echo DONE! 1>&2
+
+:done