String and EtherAddress

[Eddie Kohler]

Xiaophong,

Your String contains the ASCII representation of an Ethernet address. This
is very different from the address itself

"00:70:..." == characters 48, 48, 58, 55, 48, 58, ....
	    == hex chars  30, 30, 3A, 37, 30, 3A, ....
	    == Ethernet address 30:30:3A:37:30:3A

Use cp_ether_address() to go from ASCII representation -> Ethernet address,
and EtherAddress::s() to go the other way

Don't use Strings to pack Ethernet addresses togehter, use a
Vector<EtherAddress>

Don't use ".data()" when printing a String, use ".c_str()"; ".data()" might
leave off the terminating \0 character, causing a memory error

Eddie