SVGHMI: i18n: now loads PO filesand match translation against catalog. Refactored a bit to move i18n related code in i18n.py

SVGHMI: still WIP, now POT file is properly generated with utf-8 encoding and POEdit is launched when pressing button.

Docutil : reworked Inkscape launching and path resolution in docsvg.py

merge

Removed harmful assert in ProcessLogger.

ProcessLogger was having an assert in constructor when missing logger, leading to systematic exception when testing options accepted by compiler. This exception was silenced in ProjectController, and then MatIEC was always called without options.

SVGHMI: Intermediate commit while implementing i18n. WIP.

SVGHMI: Jump widget: switch to class based declaraion, and add some TODO comments to prepare for jump to relative page being selected through a DropDown widget.

SVGHMI: intermediate state of test/svghmi's SVG for backup... WIP

SVGHMI: CircularBar: use animate() + cormetic changes

SVGHMI: Meter widget: use animate() + cosmetic changes

SVGHMI: Update generated xslt

SVGHMI: Fix bug in keypad leading to error messages in browser console when keypas has no Shift or CapsLock keys

SVGHMI: cosmetic changes

SVGHMI: Input widget overrides undershot() and overshot() methods to display "min: xxx" or "max: xxx" when user input goes out of given range.

SVGHMI: Added clipping to min and max value for all widget using @path,min,max syntax. Added overshot() and undershot() methods to widget base class, called when value is limited to max or min respectively.