May 24, 2017
* return DroiError if callServer fails directly
* Add Http error msg if network timeout
* Add some error-handling
May 19, 2017
 * Refine DroiUser/DroiCloud for reference
May 18, 2017
* Add header
Apr 21, 2017
* Reserved more memory space
Apr 20, 2017
* Fix build break on android
* Update ErrorCode
* Fix DroiUser signup
Apr 19, 2017
First release
Mar 1, 2017
First release