Update nack dependency for better json behavior

Fixes 37signals/pow#378 and fixes 37signals/pow#416
Build with vendored CoffeeScript version
Fix failing DnsServer test by hard-coding a port
Pow 0.4.2
Vendor Docco
Merge pull request #424 from kjg/patch-1

Update nack dependency for better json behavior
Pow 0.4.3