Hold-out's database spliting method and the capacity of computing the distance matrix.
Merge branch 'master' of github.com:theodori/WebRecommendation

It is my 1st merge, in a real project, not doing proves. We will see if I do correctly.
I can see that all ssource files you have added are in package ehupatras.suffixtree, so it will not be difficult.
In my part I add the hold-out methodology and the computation of the distance matrix.