Merge pull request #65 from chaizhenhua/remotes/trunk

Nginx Improved: if "SecResponseBodyAccess off" do not copy response body...
Merge pull request #67 from chaizhenhua/remotes/trunk

Nginx Improved response body filter, issue #56 might be fixed
Merge pull request #70 from chaizhenhua/remotes/trunk

Nginx Improved: set filter_need_in_memory flag
Nginx: minor improve