Merge branch 'sev/crosshairs_size' into 'master'

Crosshair size

I've noticed that the default scale of the crosshairs is quite small. This causes aliasing issues, even at a resolution of 1920x1080, esp. for the per-weapon crosshairs.

With this branch I propose to slightly increase the default scale of all crosshairs from 0.3 to 0.4, as well as to increase some of the per-weapon crosshair scales,
to improve the first impression.

Before/After (1920x1080):
![crosshairs](https://gitlab.com/uploads/xonotic/xonotic-data.pk3dir/15a0b111db/crosshairs.png)

See merge request !104