PointsTo: add definitions of declared class members

for classes PointsToCategories && PointsToGraph

Hmm, I forget that I have made few more changes, so the commit
is not nice.. but.. what the hell.
PointsToGraph: add dump function

it's handy when debugging
tests: add points-to-test

actually it's not a test, it just dump PointsToGraph that is created
according some sequence of a->b assigments
I'm happy it looks like it works :)