Potential memory leak of map textures

Summary

I suspect there is a memory leak of map/layer textures because the amount of textures only goes up and never goes back to the initial amount, even when zoomint out.

Steps to reproduce

1. Open the inspector > processing > memory
2. Open any example with a map
3. Zoom in to load additional data
4. Zoom out so that only 1 root tile is displayed.

Expected behaviour:

The number of textures goes down to its initial value (or close to it) when we zoom out.

Actual behaviour:

The number of textures remains abnormally high.

Informations

• Giro3D version: 0.34
• Browser (Firefox, Chrome, Opera, Safari...) and version: Chrome
• OS (Linux, MacOS, Windows...) Linux