v1.2.0: Update to v1.1.0 (1st transfer from previous ThreadTune repository)

1. Major change to drawing Helix. Option to draw single revolution Helix with thread profile for length of threading, Center-line guide rail with single revolution helix or Long length helix with only 1 thread profile. 1st option of Single helix path is considerably faster for longer length threads. Long length helix can bog fusion down & can even crash it on long length threads. Center-Line guide rail does not work very often, but left it in just in case fusion changes the way it handles this later.
2. Fixed error in calculation of YB_B & YB_T used in the drawing thread profile.
3. Fixed the M8 entry in the metric_V2.txt thread style entry. The field after the Pitch had a '.' instead of a ','

Here is an example of speed difference between Helix & LongHelix option:
using the settings M12x1.75 30mm Height 30deg top & bottom angle and 18 spline points
Helix elapsed time is 3.64 seconds on my machine with virtually no difference
LongHelix elapsed time is 11.65 seconds on my machine.

These threads are not 100% accurate probably because the helix is an approximation, but should be close enough for 3d printing which this program was written for. My measurements show being off by 0.0054% (30.0016 instead of 30.0 deg angle) & 0.05% (30.014 instead of 30.0 deg angle)