SVGHMI: Prepare accepting multiple clients on multiple HMI: Use POULibrary new capability to add variables to PLC Configuration. Now heartbeat and HMI tree root are added by the library part of SVGHMI, and not by each instance.

IDE: Allow POU Libraries to inject PLC Configurations globals during build.

SVGHMI: DnD UI: Add hint instructing user to Drag HMI tree items to text field.

SVGHMI: update generated XSLT files

SVGHMI: DnD UI: Fix SVG gen that was dropping widget name and making XSLTExceptions plus some UX enhancements.

removed useless import

SVGHMI: DnD UI: SVG for DnD now generated again based on paths and args entries filled by user.

merge

SVGHMI: UI: added prefill of arguments according to values in widget instance in library. Also added library's widget instance description to description field.

IDE: Fixed variable traces graphs RingBuffers. Removed an apparently useless wxCallAfter in trend graph that was leading to pydeadobject exception on wxGTK when double-clicking.

IDE: Cleaned up some useless tests in variable trace data handling code, changed from bare numpy arrays to RingBuffers inorder to avoid RAM outage and crash after long tracing session.

IDE: Log: Prevent crash when display progress on empty log.

merge

Copy description when DnD variables from CodeFile CTN to POUs