Incorrect/Misleading Expert Documentation For Drools XML Language

The Drools XML language "...has not been developed since drools 4.0, and is considered a deprecated feature." However, the docs for 5.x versions of Drools clearly state, "All the features are available with XML that are available to DRL." As such,the docs need to be updated to reflect the current state of the XML language so users are not mislead.

A simple yellow Warning box at the beginning of the XML section stating that the XML hasn't been developed since 4.0 and is consider deprecated will be enough to properly inform users. Removing the "All features..." would be useful as well.

I'm planning to provided a pull request in the next week or so.