Improvements

Created by: VLanvin

A whole bunch of small improvements.

Changes :

• Added a faster way to create colors (ex. Color.rgb ~alpha:0.5 1.0 0.0 0.0)
• Added a clock and counter system
• It is now possible to fix a framerate limit in OgamlGraphics.Window
• Bold parameter in text now defaults to false
• Added a faster way to create vector (ex. Vector3i.make 3 5 1)
• Added pointwise operations on vectors

Breaking changes :

• Old function Color.rgb changed to Color.to_rgb
• Old function Color.hsv changed to Color.to_hsv
• Compilation now requires the -thread tag

Bugfixes :

• Fixed graph issues (#27 (closed))