- fixed the Tcl Command AlignDrillGrid
- fixed the Tcl COmmand Panelize, Excellon panelization section
- Fixed an issue in Tool Calibration export_excellon method call
- PEP8 corrections all over the app
- modified the Properties Tab for various FlatCAM objects preparing the move of Properties Tool data into the Properties Tab
- if the Properties tab is in focus (selected) when a new object is created then it is automatically selected therefore it's properties will be populated
- cleanup of the CNCJob UI; added a checkbox to signal if any append/prepend gcode was set in Preferences (unchecking it will override and disable the usage of the append/prepend GCode)
- the start Gcode is now stored in the CNCJob object attribute gc_start
- GCode Editor - finished adding the ability to select a row in the Tools table and select the related GCode
- by default now a new blank Geometry object created by FlatCAM is of type multigeo
- made sure that optimizations of lines when importing SVG or DXF as lines will not encounter polygons but only LinesStrings or LinearRings, otherwise having crashes
- fixed the import SVG and import DXF, when importing as Geometry to be imported as multigeo tool
- fixed the import SVG and import DXF, the source files will be saved as loaded into the source_file attribute of the resulting object (be it Geometry or Gerber)
