Added empty `vulture::events::EventFilter` class
In `vulture::events::EventsFilter`:
  - added public abstract `filter(Events)`
Included `EventsFilter`
Included list.
Added empty `vulture::events::FilterGroup` class
Included list.
Included memory.
Included string.
In `vulture::events::FilterGroup`:
  - added public `FilterGroup(string)` constructor
  - added public `name()` getter
  - added private _name
Renaming
In `vulture::events::EventsFilterGroup`:
  - added public `this &add(EventsFilter ptr)` method
  - added protected `_eventsFilters` field
Add some definitions.
renaming
fix
In `vulture::events::EventsFilterGroup`:
  - fixed public constructor
  - fixed protected `_eventsFilters` type
`In vulture::events::EventsFilterGroup::add(EventsFilter ptr)`:
  - now returns reference to `this`
Included string.

in `vulture::events::EventsFilter`:
  - added public `constructor(string)`
  - added public `name()` getter
  - added private `_name` field
meh
Boring definitions, just like always