clarification about handling bad/unsupported channels
adding extension idea around enabling hashname aliasing
agent stuff isn't relevant anymore, aka's are simpler
move all link timer references to one place, fixes #52
simplify and clarify link-max enforcement, to allow app usage of links independent of DHT
Fix broken link in dht.md
Merge pull request #53 from alanz/patch-4

Fix broken link in dht.md