Improved guardian keyboard control to allow runtime speed change.

Keyboard control (WASD) has two modes: running (CAPSLOCK) and walking.
Translation and rotation velocity can be changed at runtime using:
r -> decrease walking rotation velocity by 0.01 rad
R -> increase walking rotation velocity by 0.01 rad
f -> decrease running rotation velocity by 0.1  rad
F -> increase running rotation velocity by 0.1  rad
t -> decrease walking translation velocity by 0.005 m
T -> increase walking translation velocity by 0.005 m
g -> decrease running translation velocity by 0.05  m
G -> increase running translation velocity by 0.05  m