* Squashing previous commits to fix CometD bug 562
* moved MAX_MESSAGE_SIZE_OPTION to HttpClientTransport
* added getOptions method for MAX_MESSAGE_SIZE_OPTION to LongPollingTransport
* adjusted corresponding tests

added method to change the buffer size of the
BufferingResponseListener when registering the
LongPollingTransport protocol.

This allows to receive messages larger than 2 MiB

* fixes CometD bug 562
* moved MAX_MESSAGE_SIZE_OPTION to HttpClientTransport
* added getOptions method for MAX_MESSAGE_SIZE_OPTION to LongPollingTransport
* adjusted corresponding tests

* moved MAX_MESSAGE_SIZE_OPTION to HttpClientTransport
* added getOptions method for MAX_MESSAGE_SIZE_OPTION to LongPollingTransport
* adjusted corresponding tests