Add new package qingstor to support QingStor API.
Add new unit test for its and tested through; But I commented
on some tests case because of some of the features of QingStor.
Add new docs for it.
* Fix remaining problems
* Refactor to make testing easier and add a test suite
* Make path parsing more robust.
* Add single file operations
* Add MimeType reading for objects
* Add documentation
* Note go1.7+ is required to build