numpy/numpy — pull request #4751 by juliantaylor (2014-05-28 17:32:58+00:00)
Title: BUG: avoid infinite loop for small kappa in vonmises

rho results in 0. for kappa < 1.4e-8 whch leads to nans appearing and an
infinite loop.
the second order taylor expansion is more precise up to at least 1e-5.
Closes gh-4720