Texture files not caching correctly on memory

[Tercioo]

Facts:
- Whenever SetTexture() is called setting a different file makes the client load the file from the HD.

- If the file is already shown on another texture it also causes the client to load it again from the HD.

- The client is allocating memory for each individually file loaded, for instance, 3 textures showing the same file has 3 copies on memory of that file.

- Hide() is cleaning the file from the memory and Show() is loading it again from the HD.

Problems:
- With a mechanical hard drive, each Load is causing 4~10 fps drop depending on the size of the file.
- During raid encounters, this issue have a chance to scale pretty badly.