Perl as a second language

[rns]

This is of course premature and for the future, but eventually we probably need to show how to use Kollos from a language other than Lua and Perl looks like a good choice.

First things that come to mind at this early stage include a reimplementation of D2L calls (when they are sufficiently done) in Perl using Marpa::R2 thin interface and trying a Perl binding for Kollos (when its low-level calls sufficiently allow it).