Improvements in lexical-selection module

by Filip Petkovski for Apertium

The lexical selection module in Apertium is currently a prototype. There are many optimisations that could be made to make it faster and more efficient. There are a number of scripts which can be used for learning lexical-selection rules, but the scripts are not particularly well written. Part of the task will be to rewrite the scripts taking into account all possible corner cases, as well as to extend the functionality of the module itself.