GEE_est_time function

Perform GEE estimate / IRWLS of coefficients for temporal data

TO DO: eigenvalues / ndstop fix for missingness

GEE_est_time(Y, X, n, tmax, directed = TRUE, type = "EE",
  write_dir = NULL, missing = FALSE, tol.in = 1e-06, maxit = 10000,
  ndstop = TRUE, verbose = FALSE)