992a126: 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.
This should cut just enough size off the binary to let Net still compile for the c200v2. This is probably close to the last time I'll be able to do this; I'm already resorting to dirty hacks like writing super terse error messages.