Make the public documentation more Go Like.

Start all methods docs with the name of the method and make
it more readable.
Merge pull request #26 from miekg/doc

Make the public documentation more Go Like.
Move server and api into server pkg

This allows users to easily embed the
skydns server in their applications or allow
easier mocking in their tests.
Merge pull request #27 from crosbymichael/move-server

Move server and api into server pkg