Move declarations for xutil.c from notmuch-private to new xutil.h.

The motivation here is that our top-level notmuch.c main program
wants to start using these, but we don't want it to see into
notmuch-private.h, (since our main program is a test vehicle
for the "public" notmuch interface in notmuch.h).

notmuch-private.h

@@ -43,6 +43,7 @@ NOTMUCH_BEGIN_DECLS
 
 #include <talloc.h>
 
+#include "xutil.h"
 
 /* Thanks to Andrew Tridgell's (SAMBA's) talloc for this definition of
  * unlikely. The talloc source code comes to us via the GNU LGPL v. 3.
@@ -75,22 +76,6 @@ typedef enum {
     NOTMUCH_VALUE_DATE = 2
 } notmuch_value_t;
 
-/* xutil.c */
-void *
-xcalloc (size_t nmemb, size_t size);
-
-void *
-xmalloc (size_t size);
-
-void *
-xrealloc (void *ptrr, size_t size);
-
-char *
-xstrdup (const char *s);
-
-char *
-xstrndup (const char *s, size_t n);
-
 /* message.cc */
 
 notmuch_message_t *

xutil.h

@@ -0,0 +1,44 @@
+/* xutil.h - Various wrapper functions to abort on error.
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
+
+#ifndef NOTMUCH_XUTIL_H
+#define NOTMUCH_XUTIL_H
+
+#include <stdlib.h>
+#include <sys/types.h>
+#include <regex.h>
+
+/* xutil.c */
+void *
+xcalloc (size_t nmemb, size_t size);
+
+void *
+xmalloc (size_t size);
+
+void *
+xrealloc (void *ptrr, size_t size);
+
+char *
+xstrdup (const char *s);
+
+char *
+xstrndup (const char *s, size_t n);
+
+#endif