Allow factories to be passed directly to ObjectPool
Oops, fix a couple tests
Add THANKS file
Add David Wolever to THANKS
Retry pooled connections in case of BadStatusLine

Sometimes, when Apache is used as proxy, HTTP get response may raise a
BadStatusLine exception. This race condition occurs when the Apache
proxy module is being used with HTTP keepalive requests. The backend
server may close the keepalive connection right after httpd has checked
the state of this TCP connection, so httpd sends the request and waits
for a response on a connection that is in fact dead.

Solve the above error by re-sending the request when receiving a
BadStatusLine exception with empty line ('').
Bump version to 0.4rc1
Update Changelog

Update Changelog and change it's format to be in line with the one from
the Synnefo project.
Prepare for release 0.4

Remove RC versions from Changelog and add release date for
version 0.4.
Merge branch 'release-0.4'
Bump version to 0.4