Partial commit, refactored kernels code.  Need to remove the directory now.
Removed kernels package, replaced by module
Refactored kernel code to reflect its simplicity - demoted package to module.
Added to tests, now test inverse marginal cdf
Added function to evaluate trigger KDE at all interpoints using nn interpolation for improved speed.  TODO: still need to check how much of a difference this makes.
Had some real trouble with BLAS - see test_smp.py - if this works properly then all is OK.