fixed various and sundry warnings emitted by clang
kernel_estimate_regression_categorical() which affects the generalized nearest neighbor estimator only in parallel.
fixed a bug in np_kernel_estimate_con_density_categorical_convolution_cv() (parallel)
Merge branch 'master' into npRmpi
caught another glitch in kernel_estimate_regression_categorical for adaptive_nn in parallel
Merge branch 'master' into npRmpi