New feature: 'printer' Velocity template variable

[Antonio García Domínguez]

Hi everyone,

This new feature provides a 'printer' variable for the Velocity templates that can be used inside <send> elements. It references an XMLPrinterTool, which has a print(Element) method that dumps the element back as XML text. This is quite useful when some of the elements of the original request have to be repeated as-is in the response in order to correlate it or confirm that part of the request was received correctly, for instance.

It's tested and everything works as usual, so I've pushed it to bluezio/master and bpelunit/master. Comments are welcome :-).

Cheers,

Antonio