Fix 2013/cable3 for modern systems

The code declares localtime() to be a different type than what time.h
has which was included with macOS and thus it caused a compilation
error. Instead use #undef localtime (I tried to remove the prototype and
let time.h do its thing but this caused a segfault and since this works
I opted for it .. for now at least).

It also did not link in any system because it uses SDL functions that
were removed from SDL2 so sdl-config has to be used instead of
sdl2-config.

2013/cable3/cable3.c

@@ -1,5 +1,5 @@
 #include "SDL.h"
-
+#undef localtime
 #define $ for(O=9
 #define CX M+=(T%3+2*!(!T*t-6))
 #define x ,A=4*!T,O=t,W=h=T<3?u(Q?p:D(A+3),D(A),D(A+1)[i]+D(A+2)*g+):K(t),U=V=K(a),o?U=h,W=V:V,