Phi2rho - Owen's T Function and Bivariate Normal Integral

Computes 'Owen's T' function or the bivariate normal integral using one of the following methods: the modified Euler's arctangent series, tetrachoric series, or Vasicek's series. For the methodology, see Komelj, J. (2023) <doi:10.4236/ajcm.2023.134026>, or the revised postprint version with corrected contents and improved typography at <doi:10.48550/arXiv.2312.00011>. Also see the alternative approach by Vasicek, O. A. (1998) <doi:10.21314/JCF.1998.015>.