SafetyHeightFilter:
* skip move to safety height if only the height of a position changed
* simplified code

StepWidth:
* just skip small steps; don't change output formatting
* the output conversion will be done later in a more appropriate place

* before: just after the whole run - this was not enough for separate lines

* otherwise the events are not triggered after manual input (e.g. for safety height)

* this function just applies the usual "floats are within range" comparison

* this is based on a dirty copy'n'paste code piece that needs to be cleaned

* the closing move to safety height was simply forgotten
* additionally a (rarely triggered) branch was broken before

* fixed simulation speed (minutes/seconds issue)
* dynamically change speed factor step width

* removed unused debugging statements
* see: https://sourceforge.net/tracker/?func=detail&atid=1104176&aid=3546415&group_id=237831

A missing binary flag during "open" caused incomplete read operations.
Thus the length-based validation of the binary STL format failed.

value handling needs to be fixed

The file LinucCNC.py is supposed to be a good example for a machine-specific
language export definition.

* this allows to handle the filters separately instead of applying the immediately

* filters in Toolpath are now read-only and protected by property functions
* change of filters -> clear toolpath cache
* add "comment" as new toolpath record

* added "weight" attribute to allow sorting
* added PathMode (G61/G64) filter
* fixed typos in TriggerSpindle filter
* fixed typos in StepWidth filter

* random EOF (0x04) characters break the input stream in text files
* solution: open files in binary mode instead (ignoring EOF characters)

* SelectTool
* TriggerSpindle
* StepWidth

* this currently fails to expose the tool radius to the path processor

* many events are not grepped due to linebreaks

* fixed source directory
* moved the script to "scripts/"
* ignore long lines

Otherwise the "last" (based on the order of plugin initialization) toolpath
processor is selected. The load order is arbitrary - thus the initial processor
selection not determined. (we don't like this)