Move existing testCalls.lua

We'll be generating a new one, but these tests are still useful
Add script for generating basic docs and call tests
Add initial generated docs
Add initial generated tests
Remove tests for choice function
Fix issue #2 - generating into multidimensional tensors

Also add more call tests
Implement Poisson CDF function using cephes

(not vectorised at present)
Tidy and extend poissionPDF tests
Add poissonCDF, and tests
Add docs for poissonPDF and poissonCDF
Replace cephes.igamc with cephes.pdtr
Add poissonLogPDF, with tests and docs
Add gaussianPDF and gaussianCDF, with tests and docs
Add cauchyPDF and cauchyCDF, with tests and docs
Add cauchyLogPDF, with tests and docs
Add chi2PDF, chi2LogPDF, and chi2CDF, with tests and docs
Add laplacePDF, laplaceLogPDF, and laplaceCDF, with tests and docs
Add test for multivariate gaussian
Add multivariateGaussianPDF
Simplify tests to match ftureu multivariate tests