[Rd] solve cdf for noncentrality (PR#11527)

[Jerry.Lewis at biogenidec.com]

Full_Name: Jerry W. Lewis
Version: 2.7.0
OS: Windows XP Professional
Submission from: (NULL) (198.180.131.16)


The current distribution function naming convention inherited from S (d*, p*,
q*, r* for pdf/pmf, cdf, quantile, & random numbers) is inadequate for
noncentral distributions, where there is frequently a need to solve the equation
p*(...)=p for the noncentrality parameter instead of the quantile.