Implementation of Probability and Learning sections of AIMA4E branch

Having a keen interest in the domain of Artificial Intelligence, I would like to propose to write and refactor sections of the code for the AIMA4E branch "core" module in the specific areas of probability and learning. I would use the language features of Java 8 to write shorter and readable code, as well as code efficient implementations that do not sway away from the pseudo code. After having gone through several of the open issues that are flagged as TODOs, I have come up with a list of issues I find myself in a capable position to work upon. Depending upon the scope of requirements, I would also be interested in working on some visualization modules of algorithm results that provide a clearer picture of its working.