FS /dev fix; add 'objects' cmd.

kernel/ata.s:
	in ata_list_drive, print proper drive nr relative to ATA
	controller (i.e. ATA1, Drive 0 instead of ATA1, Drive 2).

kernel/dev.s:
	fix generating dev_name (hda,hdb,hdc,hdd).
	(was: hda,hda,hdb,hdb).

	fix cmd_dev_list, using class_instances, class_instanceof.

kernel/fs.s:
	fs_root_nextentry$: fix printing contents of /dev,
	using class_instances/instanceof.

kernel/oo.s:
	add class_instanceof.

	add class_get_by_name (string).

	add cmd_objects, to list all objects, filtered by (super)class.

kernel/shell.s:
	register cmd_objects.
TCP send buffer fix.

kernel/net/tcp.s:
	Fixed memory overwrites.
	Recoded sendbuf, using a sendbuf_flush_partial$ method that only sends
	max-sized packets, and does not set PSH (as this is supposed to happen
	in sendbuf_flush). Buffer is compacted to ensure max-sized packets.
ATA/ATAPI capacity fixes.

kernel/ata.s:
	fix calculating drive capacity for ATA. Use LBA28 if LBA_EXT is 0.

	fix printing IDENTIFY strings (model, serial).

	change ata_get_capacity to query for it in case of ATAPI drive.

	fix atapi_read_capacity returning CF=1 when ATAPI_DEBUG=1.
HTTPD mime-type support; fs_stat flags.

kernel/fs.s:
	fs_stat: return the flags in al to test for file/dir.

kernel/net/httpd.s:
	check whether path is a file or dir using fs_stat,
	and append /index.html if it is a dir.

	add mime-type support for a few common mime types.

root/www/index.html:
	minor changes.