Add the capacity to record POST body and access it from proxy manager's records.
Add the setting for storing POST body.
Change document.
Merge pull request #271 from neversay/master

Add the capacity to record POST body and access it from proxy manager's ...
First demo test for proxy with recording post body.
Complete the test.
Preparing for v 0.6.7
Merge pull request #273 from neversay/master

demo test for proxy with recording post body.