REDCORE-238 Add redCORE standarised packager

Adds a generic copier script to be used by extensions distributing redCORE framework in its own package.
REDCORE-238 reuse generic redCORE PHING prepare

This pull renames the PHING generic redCORE script for prepackaging redCORE framework. Also modifies the extension_packager to reuse the new redcore_compy_mandatory.xml script so in the future there is only one place to be modified if new extensions are incorporated to redcore
Merge pull request #334 from javigomez/REDCORE-238b

REDCORE-238 Add redCORE standarised packager