(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
(TK-84) Don't double encode query strings

The Java URI class encodes the "query" parameter when using its
multi-parameter constructor. In proxy-servlet we are using getQueryString
to get the query string to pass into URI, which does not URL decode the
query string. This change decodes the query string before passing it into
the URI class, which will then go ahead and reencode it.
(TK-84) Change :refer to :as

Use :as instead of :refer to improve readability.
Merge pull request #85 from fpringvaldsen/TK-84_double_encoding

(TK-84) Don't double encode query strings
PE-5869 Provide error details on proxying failure