gmoccapy_1_1_5 - allow hide axis 4 ; set DRO size

ver. 1.1.5
- added a option to hide the 4'th axis, this is useful if that axis is used
  to control a tool changer, as than the axis DRO and jog button are not needed.
  This has to be activated on the settings page, axis 4 is shown by default.
  This needed some code rework (moving code around)
- solved the problem of pin_value changes on start up / initializing, because I
  introduced a new intern variable self.initialized, leaving defs if not True
- introduced a adjustment widget on the settings page to allow the user to set
  the font size of the DRO, it will be reduced by 3/4 if 4 axis are used