Compile correctly even if i18n (libintl/gettext) is not available.

configure checks for the availability of i18n, but if it's not there,
we weren't doing anything sensible.  Now, we just use the English
constant text strings in the code by defining _(x) and N_(x) to be just
(x).

ChangeLog

+2012-09-06
+
+	* gtk-dialog.c:
+	* gtk-ui.c:
+	* ui.c:
+	* otr-plugin.c: Compile correctly even if i18n (libintl/gettext)
+	is not available.
+
 2012-09-04
 
 	* README: Release 4.0.0

gtk-dialog.c

@@ -48,6 +48,9 @@
 #ifdef ENABLE_NLS
 /* internationalisation headers */
 #include <glib/gi18n-lib.h>
+#else
+#define _(x) (x)
+#define N_(x) (x)
 #endif
 
 /* libotr headers */

gtk-ui.c

@@ -42,6 +42,9 @@
 #ifdef ENABLE_NLS
 /* internationalisation header */
 #include <glib/gi18n-lib.h>
+#else
+#define _(x) (x)
+#define N_(x) (x)
 #endif
 
 /* purple-otr headers */

otr-plugin.c

@@ -56,6 +56,11 @@
 /* internationalisation header */
 #include <glib/gi18n-lib.h>
 
+#else /* ENABLE_NLS */
+
+#define _(x) (x)
+#define N_(x) (x)
+
 #endif /* ENABLE_NLS */
 
 /* libotr headers */

ui.c

@@ -34,6 +34,9 @@
 #ifdef ENABLE_NLS
 /* internationalisation header */
 #include <glib/gi18n-lib.h>
+#else
+#define _(x) (x)
+#define N_(x) (x)
 #endif
 
 /* libotr headers */