Add more doc strings to the lock implementation.
Add more doc strings to the lock implementation.

tempbottle/kazoo,bsanders/kazoo,max0d41/kazoo,rgs1/kazoo,kormat/kazoo,Asana/kazoo,python-zk/kazoo,jacksontj/kazoo,rackerlabs/kazoo,AlexanderplUs/kazoo,max0d41/kazoo,jacksontj/kazoo,bsanders/kazoo,rockerbox/kazoo,harlowja/kazoo,pombredanne/kazoo,kormat/kazoo,AlexanderplUs/kazoo,rgs1/kazoo,rackerlabs/kazoo,tempbottle/kazoo,pombredanne/kazoo,harlowja/kazoo,rockerbox/kazoo,python-zk/kazoo