An attempt to better support ActiveMQ.  Inclusion of the content-length header, although correct by Stomp protocol standards, is actually a flag for ActiveMQ to consider whether the message is a JMSTextMessage, or JMSByteMessage.
For clarification, see under "Working with JMS Text/Bytes Messages and Stomp":
http://activemq.apache.org/stomp.html
This proposes the inclusion of a 'suppress-content-length' header than can be passed in when creating the stomp client.
Doing so allows us to send TextMessages rather than BytesMessages to ActiveMQ.

Although this is an ActiveMQ deficiency, seems like Ruby Stomp Clients have been using a similar "hack" for a while.