Camera inertia takes way too long to finish

[mramato]

I noticed both in the camera move events example and via #2838 that the camera inertia takes several seconds to finish after the user lets go of the mouse. It seems it continues to move a minuscule amount < 1 meter for several seconds. This greatly decreases the usefulness of the move events because it creates what is perceived as lag. We should shorten the inertia or have a cut off that once the inertia is less than a certain amount, we just stop.

[hpinkos]

related: #2715