All tests for reactive system green
Fixed merge conflicts
Cleanup. Triggering and mandatory components are now always matchers. Clarified some behaviour of matchers with empty component sets.
Renaming, clarified more edge cases around matchers
Added a few different varieties of creating reactive systems.
Merged upstream changes
Added fourth version of reactive systems, where everything is in the subsystem
Performance improvements
fixed some whitespace issues
Revert "fixed some whitespace issues"

This reverts commit ca4a8d26eccc535f37b8cadb7e9a0a0105977067.
Added a variation of version 5 with a setUp method instead of returning values
Merge branch 'master' into feature-reactive-systems
First implementation of repository observer
Merge branch 'master' into feature-reactive-systems
Added more tests, activation/deactivation and trigger by component removal
💄 Removed old reactive systems, code cleanup
Removed some intermediate code
Update ESEntity.m
Update ESMatcher.m
Update ESRepositoryObserver.h