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/python/regress/testhelpers.h

@@ -23,7 +23,7 @@
 
 #include "../pyhelpers.h"
 
-#include "sudo_conf.h"
+#include <sudo_conf.h>
 
 // just for the IDE
 #ifndef SRC_DIR