Test message element

[rasevicrade]

Hi,

I just want to say great work on the framework. We've been using it for a while and have a minor suggestion for the signature of assertions. It would be great if it accepted XML as a "message".
So for example if one was to use:
assert:true(fn:false(), <a>Wrong!</a>)
Output would be:

<assert test="true" result="failed" xmlns="http://github.com/robwhitby/xray">
  <actual>false</actual>
  <expected>true</expected>
  <message>
    <a>Wrong!</a>
</message>
</assert>

In any case, keep up the good work!