clarify hashsize typepdef in assoc.c to be 32-bit
no bug, but confusing code.
static pthread_cond_t maintenance_cond = PTHREAD_COND_INITIALIZER;
static pthread_mutex_t maintenance_lock = PTHREAD_MUTEX_INITIALIZER;
-typedef unsigned long int ub4; /* unsigned 4-byte quantities */
+typedef uint32_t ub4; /* unsigned 4-byte quantities */
typedef unsigned char ub1; /* unsigned 1-byte quantities */
/* how many powers of 2's worth of buckets we use */
