Use double-precision floating point numbers instead of single-precision

[Unarelith]

Using single-precision floating point numbers can seriously affect bounding box and meshes that are far from (0;0;0).

However using double-precision floating point numbers can affect performance and data transfers.

Evaluate the pros and cons of such a change.

Thanks to p_gimeno for pointing this out.

Notes

• At 500 000, 500 000, there's precision issues with the player movement and the camera
• OpenGL should still use single-precision floating point numbers to avoid impacting performance too much
• One way to do that would be render the world depending of the camera coordinates

[Unarelith]

Fixed by @p_gimeno

PR: https://git.unarelith.net/Unarelith/OpenMiner/pulls/9

Commits:

• af1a641
• 4bb12c8
• 6e3c2e0
• 33dca07
• d4daaa6
• 6e506d8