moodle-tool_mergeusers - several improvements:
    * lib/autoload.php to enable autoloading of classes from the plugin. Removed lib/lib.php
    * moved locallib.php to lib/mergeusertool.php to enable autoloading.
    * updated README.txt for new Gatherings.
    * Ctrl+C is moved from Gathering to Merger class, to remove this responsibility from new Gathering implementations.
Merge pull request #16 from jpahullo/improvementsonlib

moodle-tool_mergeusers - several improvements: