2.0.0-pre2

• added user defined functions (see https://github.com/docb/dbRackFormulaOne#waveshaping)
• added some convenient global functions
  • lseg provides line segments for a given phase and coefficients
  • eseg provides exponential curve segments for a given phase and coefficients
  • scl scales a value from one range to another
  • scl1 scales -1V/1V to a given range
  • poly computes a polynomial for a given phase and coefficients
  • chb computes a sum of chebyshev polynomials for a given phase and coefficients
  • tri computes a triangle wave for a given phase
  • spl computes a spline for a given phase and coefficients
• compiled now for windows with extended features (linking costs half an hour)
• fixed some gui issues for better editing