Updating xqDoc to current XQuery versions 1.0-ml and 3.1

I had previously been working on the xqDoc ANTLR and Java code to handle the changes to the XQuery language.  The codebase that I downloaded included the invoked functions and the referred to variables.

I have added annotations as well as some of the XQuery 3.1 additions into the antler file https://github.com/lcahlander/xqDoc/blob/master/src/org/xqdoc/xquery/parser/jul2017/XQuery.g <https://github.com/lcahlander/xqDoc/blob/master/src/org/xqdoc/xquery/parser/jul2017/XQuery.g>

It requires the antlr-2.7.5 jar file.

I have checked in the code at https://github.com/lcahlander/xqDoc <https://github.com/lcahlander/xqDoc>

It would be good to have test case XQuery files to run the parser against so that it handles all of the enhancements to the language.

I think that it needs to become an EXPath module.

I would like feedback from folks.