[glom] Add an appdata-validate target.

[Murray Cumming <murrayc src gnome org>]

commit ee14a3f18cd23004bb8f7096d10b61a03c785b68
Author: Murray Cumming <murrayc murrayc com>
Date:   Wed Oct 2 10:13:00 2013 +0200

    Add an appdata-validate target.

 Makefile.am |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/Makefile.am b/Makefile.am
index 6fd68ce..49a61c7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -240,6 +240,7 @@ desktop_DATA = glom.desktop
 endif
 
 
+# The AppData file:
 appdatadir = $(datadir)/appdata
 
 if HOST_WIN32
@@ -248,6 +249,11 @@ else
 appdata_DATA = glom.appdata.xml
 endif
 
+#Validate the AppData File:
+#TODO: Run this during make check when appdata-tools is widespread.
+validate-appdata:
+       appdata-validate --strict $(appdata_DATA)
+
 
 mimedir = $(datadir)/mime
 mimepackagesdir = $(mimedir)/packages