To activate, use `SetParticleType(int type)`. To deactivate, use `DisableParticle()`.
Types are:
- PT_DEFAULT (default value; uses `gl_particles_style`)
- PT_SQUARE
- PT_ROUND
- PT_SMOOTH
While in this mode:
- `Texture` & `Translation` are ignored
- `Scale.X` sets the size
- `SColor` sets the color
Misc changes:
- Removed warning on textureless destruction
Now uses its own self-managed linked list with its level tracking the head pointer. Allows for VisualThinkers to be moved to any desired stat instead of being stuck in STAT_VISUALTHINKER.
* remove duplicated fields
* make native functions use direct calls
* remove unnecessary pointer from particle_t
* create HWSprite directly in Construct
