(TK-43) Fixy query param issue with proxy

Previously, a proxy handler added to a server would crash when
given a query parameter. Fix this issue and add test to validate
it works.
(TK-43) Address comments on PR

Change URI to be a StringBuilder to preserve as much of
old code as possible. Add additional query params test. Further,
change some variable names in tests and docs.
Merge pull request #44 from fpringvaldsen/TK-43-proxy-fails-query-param

(TK-43) Fix query param issue with proxy