EZP-19948 - Added base GlobalHelper class and defined it as a service
EZP-19948 - Fixed missing argument to ezpublish.twig.global_helper.core service
EZP-19948 - Registered "ezpublish" global variable in Twig
EZP-19948 - Simplified Twig global load, directly from an extension
EZP-19948 - Added base legacy helper
EZP-19948 - Expose legacy meta information from content module, including css/js from ezjscore
EZP-19948 - Expose config resolver
EZP-19948 - Added tests
Merge pull request #206 from ezsystems/globalTwigHelper

Implemented EZP-19948 - Global variable available in twig