(TK-31) Increase proxy request buffer size

Double the size of the request buffer on an HTTP Client. This
will fix the proxy issue that occurs when making a request
with an extremely large cookie like the one seen in TK-31.
(TK-31) Make header size configurable for proxy

Allow the user to configure the request header size for a proxy
request.
(TK-31) Increase proxy request buffer size

Double the size of the request buffer on an HTTP Client. This
will fix the proxy issue that occurs when making a request
with an extremely large cookie like the one seen in TK-31.
(TK-31) Make header size configurable for proxy

Allow the user to configure the request header size for a proxy
request.
Merge branch 'TK-31-proxy-explosion' of https://github.com/fpringvaldsen/trapperkeeper-webserver-jetty9 into TK-31-proxy-explosion
(TK-31) Update proxy options in Readme

Update the list of proxy options in the README file to include
the new request-buffer-size option.
(TK-31) Add proxy explosion test

Add test that ensures that a proxy request explodes when given
an extremely large cookie and the request buffer size is not
configured.
(TK-31) Add cookie to ring handler response

Add cookie to the body of a successful ring handler response. If
no cookie is provided, the body will be unchanged, but if a cookie
is provided, this validates that the cookie exists and is not
being truncated.
(TK-31) Ensure default request buffer size

Explicitly set the request buffer size to 4096 bytes if no
request buffer size is specified in the proxy options.
Merge pull request #38 from fpringvaldsen/TK-31-proxy-explosion

(TK-31) Fix bug with large cookie on a proxy request