Use #include <foo.h> instead of #include "foo.h" in most cases.

We rely on the include path to find many of these headers.  It
especially doesn't make sense to use #include "foo.h" for headers
in the top-level include directory.

plugins/sudoers/timestamp.c

@@ -41,8 +41,8 @@
 #include <pwd.h>
 #include <signal.h>
 
-#include "sudoers.h"
-#include "timestamp.h"
+#include <sudoers.h>
+#include <timestamp.h>
 
 #define TIMESTAMP_OPEN_ERROR	-1
 #define TIMESTAMP_PERM_ERROR	-2