Ipns name resolution

This branch is not yet complete, but before i move forward, the name resolution code (in namesys) needs some critiquing. There are also a decent number of bugfixes in this branch that i ran into while trying to get the code to a point where i could test ipns.
still wondering about this. may be enough to store the key with regular ipfs. i guess the issue there is ensuring some nodes storing the keys are online at all times, which the dht gives us. hm.