The Windows RNG turns out to only give about 16 bits at a time. This

is (a) pretty feeble, and (b) means that although Net seeds transfer
between platforms and still generate the same game, there's a
suspicious discrepancy in the typical seed _generated_ by each
platform.
I have a better RNG kicking around in this code base already, so
I'll just use it. Each midend has its own random_state, which it
passes to new_game_seed() as required. A handy consequence of this
is that initial seed data is now passed to midend_new(), which means
that new platform implementors are unlikely to forget to seed the
RNG because failure to do so causes a compile error!

[originally from svn r4187]

misc.c

@@ -7,23 +7,6 @@
 
 #include "puzzles.h"
 
-int rand_upto(int limit)
-{
-    unsigned long divisor = RAND_MAX / (unsigned)limit;
-    unsigned long max = divisor * (unsigned)limit;
-    unsigned long n;
-
-    assert(limit > 0);
-
-    do {
-        n = rand();
-    } while (n >= max);
-
-    n /= divisor;
-
-    return (int)n;
-}
-
 void free_cfg(config_item *cfg)
 {
     config_item *i;