(WIP) Add access logging to jetty
(TK-81) Add docs and test for request logback

Add a test for the new request logback feature. Add docs
explaining how to use the new configuration option.
(TK-81) Move custom appender

Move custom appender so that Travis can load it.
(TK-81) Address PR comments

Add example logback config file to docs folder. Clean up some
import statements. Add a comment explaining why the thread
needs to be slept in the request logging test.
Merge pull request #82 from fpringvaldsen/TK-81-request-logback

(TK-81) Add docs and example to request logging feature