Types: make SilcUInt32 an unsigned int in most cases.

On typical 32-bit systems, both unsigned int and unsigned long are 32
bits wide.  However, they have different format specifiers, so they
cannot be used interchangeably.  On typical 64-bit systems, unsigned int
is 32 bits and unsigned long is 64 bits.  To allow for a more consistent
format string, reorder the type size checks so that SilcUInt32 is an
unsigned int on both 32 bit and 64 bit systems.