Support doTry class references

[AlanFoster]

We should add support for the doTry DSL.

For example

<doTry>
        <to uri="..."/>
        <doCatch>
            <exception>java.io.IOException</exception>
            <exception>java.lang.IllegalStateException</exception>
            <to uri="..."/>
        </doCatch>
        <doFinally>
            <to uri="..."/>
        </doFinally>
    </doTry>

Some more examples of the doTry XML DSL is at the bottom of the apache camel documentation http://camel.apache.org/try-catch-finally.html

[AlanFoster]

This exception DSL relates to #1 and #7 too