gnu: Add itstool.

* gnu/packages/glib.scm (itstool): New variable.

gnu/packages/glib.scm

@@ -186,6 +186,40 @@ The intltool collection can be used to do these things:
     oaf files. This merge step will happen at build resp. installation time.")
     (license license:gpl2+)))
 
+(define-public itstool
+  (package
+    (name "itstool")
+    (version "1.2.0")
+    (source (origin
+             (method url-fetch)
+             (uri (string-append "http://files.itstool.org/itstool/itstool-"
+                                 version ".tar.bz2"))
+             (sha256
+              (base32
+               "1akq75aflihm3y7js8biy7b5mw2g11vl8yq90gydnwlwp0zxdzj6"))))
+    (build-system gnu-build-system)
+    (home-page "http://www.itstool.org")
+    (synopsis "Tool to translate XML documents with PO files")
+    (description
+     "ITS Tool allows you to translate your XML documents with PO files, using
+rules from the W3C Internationalization Tag Set (ITS) to determine what to
+translate and how to separate it into PO file messages.
+
+PO files are the standard translation format for GNU and other Unix-like
+systems.  They present translatable information as discrete messages, allowing
+each message to be translated independently.  In contrast to whole-page
+translation, translating with a message-based format like PO means you can
+easily track changes to the source document down to the paragraph.  When new
+strings are added or existing strings are modified, you only need to update the
+corresponding messages.
+
+ITS Tool is designed to make XML documents translatable through PO files by
+applying standard ITS rules, as well as extension rules specific to ITS Tool.
+ITS also provides an industry standard way for authors to override translation
+information in their documents, such as whether a particular element should be
+translated.")
+    (license gpl3+)))
+
 (define-public dbus-glib
   (package
     (name "dbus-glib")