In `vulture::events::EventsFilter`:
  - abstract `filter(Event)` now returns `bool`
In `vulture::events::EventsFilterGroup`:
  - added `filter(Event)->bool` method
In `EventsFilterGroup::filteR(events)->bool`:
  >if one of the filter was able to filter events:
    >return true
  >else:
    >return false
In `vulture::events::System`:
  - added public `addFilters(shared_ptr<FiltersGroup>)` method
  - added protected list<sharded_ptr<FiltersGroup>> _eventsFiltersGroup` field
fixed type
Added `events/System` source file;

Added definition of `System::addFilters(group_ptr)` method
In `vulture::events::System`:
  - added protected `handleEvents(events)` method