Changes

• fixed #1 Unable to post json data
• fixed #2 Overwrite for existing headers in set_header method

• fixed unchanged Host header when recall
• fixed wrong control about https protocol
• support case insensitive about protocol
• fixed ssl certification verify problem
• enhanced error detecting
• support auto redirect

• fixed relay error when sent with url-encode method
• fixed ignored httphost header arguments on head/relay/fetch APIs

• fixed missing 3th argument when call set_header method

• add head method for requesting HTTP/1.1 HEAD method

• fixed typo CURL_FAILONERROR to CURLOPT_FAILONERROR
• add myException dependency
• add posttype public property ('form-data', 'url-encode')

Initial release