optimised nearest mean classifier

Based on version by Cesare Magri
Poisson naive bayes classifier
clean up variable names
fix variable names
optimised diagonal linear classifier

gaussian naive bayes
add gitignore
replace bsxfun for performance
correct function name
fix variance update

needs to use old + new means in Knuth formula
linear loo classifier
optimised diagonal quadratic classifier
optimised quadratic classifier
add documentation
optimised multinomial bayes
add multinom to readme
clean up variables
clean up code (removed unused commented sections)
minor update to readme
knn classifier with loo

using matlab kdtree from statistics toolbox
move to single call to knnsearch