* remote.c: Change PBUFSIZ back to 400. John's 28 Feb 1992 change

	* remote.c: Change PBUFSIZ back to 400.  John's 28 Feb 1992 change
	to increase it broke the ability to write large chunks of memory
	with m68k-stub and i386-stub.  Now we only use more than 400 on
	machines where we need that much to write the registers.
	* remote.c (remote_write_bytes): Eliminate possible abort().  The
	check for when to abort was off by a few bytes and besides which,
	it is handled by MAXBUFBYTES, which the caller uses.
	* m68k-stub.c: Add comments about trap #1 and trap #8 instructions.