Added code to allow more than one param with the same key.
Merge pull request #68 from joebroni/master

Allow more than one Request param with the same key.
Fixed: Exception black/white list in RetryHandler not checked against child classes like ConnectTimeoutException, causing connection hang when the destination is unreachable.
Merge pull request #171 from daveyfong/connection-hang-fix

Fixed connection hang when host unreachable
fix conflict