Updated client to not clobber user agent when setting default headers
Adding Accept-Encoding header now sets CURLOPT_ENCODING - fixes #217
Changes value of CURLOPT_SSL_VERIFYHOST set in Http Client

1 as a value for CURLOPT_SSL_VERIFYHOST is deprecated
in libcurl 7.28.1, recommended value is now 2
Fixing redirect response chaining. Closes #223