Linear1Pass 1st attempt part 2

Linear 1 Pass focus algorithm 1st release. Contain the code for the Linear 1 Pass algorithm offering:

• Hyperbola and Parabola fits.
• Weighted / unweighted datapoint fitting, based on standard deviation of star HFRs.
• Calculation of degree of curve fitting (R-squared) and re-run if below user defined threshold.

This is the second MR as the first one had some compile issues for reasons unknown.