64-bit fixes.
 [jmk] --rw-rw-r-- M 1092710 glenda sys 3334 Dec 29 17:31 sys/src/libmemdraw/alloc.c
	/n/sourcesdump/2005/1229/plan9/sys/src/libmemdraw/alloc.c:130,136 - 
	/n/sourcesdump/2005/1230/plan9/sys/src/libmemdraw/alloc.c:130,136
	  ulong*
	  wordaddr(Memimage *i, Point p)
	  {
	- 	return (ulong*) ((ulong)byteaddr(i, p) & ~(sizeof(ulong)-1));
	+ 	return (ulong*) ((uintptr)byteaddr(i, p) & ~(sizeof(ulong)-1));
	  }
	  
	  uchar*
 [jmk] --rw-rw-r-- M 1092710 glenda sys 1290 Dec 29 17:31 sys/src/libmemdraw/defont.c
	/n/sourcesdump/2005/1229/plan9/sys/src/libmemdraw/defont.c:21,27 - 
	/n/sourcesdump/2005/1230/plan9/sys/src/libmemdraw/defont.c:21,27
	  	 * declared as char*, not ulong*.
	  	 */
	  	p = (char*)defontdata;
	- 	n = (ulong)p & 3;
	+ 	n = (uintptr)p & 3;
	  	if(n != 0){
	  		memmove(p+(4-n), p, sizeofdefont-n);
	  		p += 4-n;