Interval Algebra - Composition - Done

This is, hopefully, the last PR for the IA task. After nearly one year of hard work, it seems finished to me.

The IA impl is currently an stand-alone app, no glue code has been written yet to make it work with the rest of OC, since there are some design decisions to be made which first need consulting with @bgoertzel and the rest of the team.

The code currently has zero documentation. I'm planning to allocate a few months of work doing this, since this involves writing a journal paper first, and after it got accepted, mostly copy and paste the content into Wiki.

@linas now I will have some spare time to work with you on the LG-UI, if you wish...