Get GnuCash building again.

- move the #include of g18n.h from gnc-date.h to gnc-date.c
- add gnc-date.c to POTFILES.in

git-svn-id: svn+ssh://svn.gnucash.org/repo/gnucash/trunk@17250 57a11ea4-9604-0410-9ed3-97b8803252fd

lib/libqof/qof/gnc-date.c

@@ -41,6 +41,7 @@
 #include <time.h>
 
 #include <glib.h>
+#include <glib/gi18n.h>
 
 #include "gnc-date-p.h"
 #include "qof.h"

lib/libqof/qof/gnc-date.h

@@ -68,7 +68,6 @@
 #define GNC_DATE_H
 
 #include <time.h>
-#include <glib/gi18n.h>
 
 /** The default date format for use with strftime. */
 extern const char *gnc_default_strftime_date_format;