May update

[JoernT]

in May we have:

• fixed some issues with <fx-var> elements but there's still one open case to be dealt with before we can rollout a fix release
• refined iterate demo
• fixed an issue in regex for function registration
• fixed error logging for instances
• created new tests

Next up:

• function libraries are high on the list meaning the ability to import extension functions from either a XQuery file or a HTML file containing <fx-function> elements.
• further work on <fx-connection>
• realize the existing plan to address the 'partial instance problem'