SVGHMI: Widget transform before DnD now have HMI path as a parameter

SVGHMI: Widget transform before DnD now should have HMI path as a parameter, but this path isn't computed for some reason... WIP.

SVGHMI: Widget DnD to Inkscape : Added source SVG widget label parsing and pass selecte HMI subtree to XSLT tranform, so that SVG containing multiple widgets can later be matched against hmi tree fragments, in order to DnD complex groups of widgets.

SVGHMI: Widget Library Picker now transforms SVG widget before allowing DnD. Transform is just identity forn now, but label parsing have already been included. To be continued.

SVGHMI: Ensure that when widgets are nested in HMI:Switch widget, their sub-elements are taken as switch's choice in case their label match the syntax.

SVGHMI: Code cleanup for ToggleButton.

SVGHMI: Fixed last i18n changes meant to allow checking changes in PO files. Was making build exception when no PO files available.

IDE: Add a shortcut to project "Clean" action : F9

merge

SVGHMI: fixed embedded fonts family name not matching when using windows version of inkscape

SVGHMI: force svghmi build if any change in fonts or translation (.PO) files

SVGHMI: Add file type drag'n'drop to widget picker, for now drops widget's original SVG.

SVGHMI: silence debug output in generated xhtml.

SVGHMI: Implemented "Add Font" and "Remove Font", add font embedding in CSS at build time, tested ok with some OTF for now.

SVGHMI: Add font management buttons and icons, doing nothing for now

Fixed misuse of GridCellEditor in DurationCellEditor, potentially leading to crash on windows.

SVGHMI: Fix update of HMI tree in UI when loading from XML at start. Removed some dead code left after split of svghmi.py into svghmi.py+ui.py.

merge

SVGHMI: added "page_node" variable that reflects the HMI tree path of current relative page

SVGHMI: Add list of HMI tree path in a JS array, so that we can use it for multiple purpose :
- display name of edited variable in keypads (currently wrong in relative pages)
- have some variable that hold basename of current relative page HMI_NODE's path
- propose some list of names in DropDown when selecting a relative page to jump to, without having to instancite many jump widgets.

SVGHMI: Fixed wierd CDATA mess in output xhtml, because of backticks copy pasted in some yml ||text block||

SVGHMI: Added fonts.py with functions to convert ttf, otf and woff fonts into data_uri based CSS font-face

merge

SVGHMI: split svghmi.py into svghmi.py (Config Tree Node + code gen) and ui.py (UI for HMI tree and Widget picking)

SVGHMI: stop serving HMI open wide on all interfaces. That was a security hole. It is user/developer responsibity to forward connection with for exemple stunnel and make it securely accessible from LAN.

SVGHMI: Filter unseen geometry from inkscape CSV output.

When inkscape exports geometry form all objects, then it also includes objects from svg:defs. This makes problems when deciding if an object is part of a page, since coordinate of objects in svg:defs can eventualy be contained in a page. In the end, those objects where getting detached when leaving pages where they where found, leading for exemple to non working text on clipping when the clipped text was cloned in multiple page.

SVGHMI: Fix typo in error message formating in i18n.

SVGHMI: split svghmi.py into hmi_tree.py + svghmi.py

Merged

SVGHMI: JsonTable: Fixed options not being passed in JSON post when jumping to a page where additional variables are pre-defined by a HMI:VarInit.
Was JS Fetch Promise not executed late enough, and gathering JsonTable variables before the sequence of calls to dispatch() was finished.