Sync with existing engine (content, behavior) + Bugfixes

Changed:

• Engine won't stop if StopTrigger is not set
• Updated readme to show available conditions/actions wrt to each engine
• InitActions are now executed when engine is initialized

Added:

• Cmake install facilities

Fixed:

• Maneuver and Story now also parse subtree (major bug)
• Fixed segmentation fault, related to lambda capture in parsing stage