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/group_plugin.c

@@ -31,8 +31,8 @@
 #include <ctype.h>
 #include <errno.h>
 
-#include "sudoers.h"
-#include "sudo_dso.h"
+#include <sudoers.h>
+#include <sudo_dso.h>
 
 #if defined(HAVE_DLOPEN) || defined(HAVE_SHL_LOAD)