Update litecoin seeds and checkpoints to match reference 0.8.x
Update litecoin seeds and checkpoints to match reference 0.8.x

Zlerp/bitcoin-ruby,tarix/bitcoin-ruby,xiumiao/bitcoin-ruby,mhanne/bitcoin-ruby,robertg/bitcoin-ruby,assafshomer/bitcoin-ruby,bitpesa/bitcoin-ruby,georgemillo/bitcoin-ruby