factor some pioneering code into a the stable building block class DSNLEXER, generalize expected valued for name and value within the template field parser.

fixed bugs 593546  ( 'Update module' in module editor becomes sometimes unavailable after undo ) and 593547  ('no' confirmation in module editor overlaps modules)

fixed bugs 593546  ( 'Update module' in module editor becomes sometimes unavailable after undo ) and 593547  ('no' confirmation in module editor overlaps modules)

* Field match method expected SCH_SHEET_PATH pointer type not SCH_SHEET
  pointer type.

Added an *experimental* tool (bitmap2component) to create logos from .bmp bitmaps. Added Potrace library to convert bitmaps to polygons
    This tool uses potarce library that converts a bitmap picture (.bmp or .pgm format) to a set of polygons.
    bitmap2component converts a bitmap to a .emp footprint (that can be imported by modedit) or a .lib component that can be    imported by libedit.
    See changelog for more info

Added an experimental tool to create logos from .bmp bitmaps. Added Potrace library to convert bitmaps to polygons

Added an experimental tool to create logos from .bmp bitmaps. Added Potrace library to convert bitmaps to polygons

fixed bugs 587175 and 587176

* Fix a minor problem with wxFileDialog to open a file that no longer
  exists in PCBNew.
* Make GerbView open file behavior the same as PCBNew.
* Remove redundant PCB file wild card definition.
* Add open file refactor task to the todo list.
* Fix some minor code formatting issues.