puzzles: update frontend for new upstream, misc. changes

The upstream code changed a little bit with regard to the request_keys()
API. Also, we save some bytes (especially on the c200v2) by compiling with
-ffunction-sections and -fdata-sections, which allows Net to fit once again.

Change-Id: I3ab30127169c73e4cd8996f0c12e1223ee18d79f

apps/plugins/puzzles/rbcompat.h

@@ -4,6 +4,7 @@
 #include "plugin.h"
 #include "rbassert.h"
 #include "lib/pluginlib_exit.h"
+#include "lib/stdio_compat.h"
 
 #include <tlsf.h>
 
@@ -77,6 +78,4 @@ double acos_wrapper(double x);
 
 #define abs(x) ((x)<0?-(x):(x))
 
-/* work around compilation error */
-typedef void FILE;
 #endif