Refresh token and http asynchronus queue

[girod]

There is a bug when we use getrefreshtoken if the page has sent multiple asynchronus http requests. Because all the http requests 'refresh_token' are sent with the first access token ... The first request is ok : we get the new access token but the next requests in the queue use the old access token. So we get a 401 error ...

[pashamesh]

+1

[ruipenso]

The changes introduced in #77 solves this issue. Closing it.

[ruipenso]

These chances was reverted and re-introduce in a major version (4.0.0) due to BC. See this comment for more information.