make subtest generation optional
link vec3helper to all tests
Merge pull request #41 from voxelinc/overlapping_prevention

Overlapping prevention
Fix roll controls and HUD inertia
Merge pull request #49 from voxelinc/fixhud

Fix roll controls and HUD inertia
Merge branch 'master' of https://github.com/voxelinc/voxellancer into physics_tests