Add view in message viewer that combines JMS Headers, Properties, and Body Text

[mlrobertson]

This might be something that could be added to #157 (Print Option), but we don't need to print. We often would like to copy the entire contents of a message in a readable format that can easily copied into and email. Currently you can do this easily with the Body (Text) contents, put if you want the entire contents of the Properties, you have to select line-by-line and perform a separate copy/paste.

[gerco]

Interesting feature. I'm not quite sure what the UI for this would look like though. Would a "copy to clipboard" button or right-click menu item work for you for example?