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/pyhelpers.c

@@ -25,7 +25,7 @@
 
 #include <pwd.h>
 #include <signal.h>
-#include "pathnames.h"
+#include <pathnames.h>
 
 static int
 _sudo_printf_default(int msg_type, const char * restrict fmt, ...)