Just like we reuse texture ids with the same size we can, at the expense
of a little memory, reuse vertex buffers if they reference the same
attributes and contain the same data.
Each VAO is marked as free at the end of the frame, and if it's not
reused in the following frame, it gets dropped.
Instead of passing the size of the buffer, we should pass the number of
quads; we know what the size of a single quad structure is, so we can do
the multiplication internally when creating the VAO.
This allows us to print the quads for debugging purposes.
We keep the textures used inside a frame around until the end of the
following frame; whenever we need a texture with the same size, and
it's not marked in use, then we just reuse the existing texture.
We want the GL driver to cache as many resources as possible, so we can
always ensure that we're in a consistent state, and we can handle state
transitions more appropriately.
Drop the texture parameters handling from the texture creation, and
associate them with the contents upload. Also, rename the function to
something more in line with what it does.
We want to add the list of FBOs tied to a texture; this means we cannot
trivally copy the Texture structure when adding it to a GArray. We're
also going to have more textures than VAOs, so it makes more sense to
use a O(1) access data structure for them.
