qiniu/csharp-sdk — pull request #23 by lonegunmanb (2013-08-23 15:01:52+00:00)
Title: Fix incorrect expire deadline set, adjust now to utc now

Orign method set the wrong expire time in +8 timezone, the api define deadline from 1970/1/1 utc/gmt, so the now's value must take DateTime.UtcNow.

And begin time's never change, consider set it static readonly.