(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
Merge pull request #84 from fhrbek/pe_5869_provide_error_details_on_proxying_failure

PE-5869 Provide error details on proxying failure