New working C-implementation of an IXML parser.

I have added IXML parsing to my existing xml/html/json tool xmq.

Today is a milestone since it parsed the ixml.ixml grammar itself and most
of the test cases in
https://github.com/invisibleXML/ixml/tree/master/tests/correct. More work
for sure to be compliant, but its working! 🎉

You use it like this:
xmq --ixml=grammar.ixml input.txt to-xml > output.xml

(If you forget to-xml you will get syntax colored xmq output, which can be
easier to read since content whitespace is visible. You can also replace
"to-xml" with "pa" for a terminal pager, or "br" for viewing the output in
your default browser.)

You can build the tool from scratch https://github.com/libxmq/xmq
and there are prebuilt binaries for GNU/Linux, MacOS and Windows.

Have fun!

//Fredrik