refactor of trigger data handling so that custom data from within the prehook becomes available in trigger data. It was also needed to add a hook for altering trigger data

Please see issue #47 here: https://github.com/CiviCooP/org.civicoop.civirules/issues/47

refactor of trigger data so it would always include a contact entity and changed the entity tag triggers

added logging to the Action and Condition classes and implemented a basic psr3 log interface and log level class