Tiger IMRPhenomXPHM

added support for non-GR waveforms through the TIGER parametrization. This patch adds the following classes (and associated tests).

• TIGERdChiMinus2Distribution
  • UniformTIGERdChiMinus2
  • TruncatedGaussianTIGERdChiMinus2
• TIGERdChi0Distribution
  • UniformTIGERdChi0
  • TruncatedGaussianTIGERdChi0
• TIGERdChi1Distribution
  • UniformTIGERdChi1
  • TruncatedGaussianTIGERdChi1
• TIGERdChi2Distribution
  • UniformTIGERdChi2
  • TruncatedGaussianTIGERdChi2
• TIGERdChi3Distribution
  • UniformTIGERdChi3
  • TruncatedGaussianTIGERdChi3
• TIGERdChi4Distribution
  • UniformTIGERdChi4
  • TruncatedGaussianTIGERdChi4
• TIGERdChi5Distribution
  • UniformTIGERdChi5
  • TruncatedGaussianTIGERdChi5
• TIGERdChi5LDistribution
  • UniformTIGERdChi5L
  • TruncatedGaussianTIGERdChi5L
• TIGERdChi6Distribution
  • UniformTIGERdChi6
  • TruncatedGaussianTIGERdChi6
• TIGERdChi6LDistribution
  • UniformTIGERdChi6L
  • TruncatedGaussianTIGERdChi6L
• TIGERdChi7Distribution
  • UniformTIGERdChi7
  • TruncatedGaussianTIGERdChi7

It also adds functionality to identify and extract non-GR parameters from events and pass them to the waveform generator.