Expand, in the Wiki, on the definition of Vector Clocks and their requirements.

[bestchai]

It is easy to misunderstand how a Vector Clock operates if you aren't fresh out of an undergrad Distributed Systems course. So explicitly defining them in the Wiki will help people more easily start using ShiViz. For example, a user has commented:

"What I really did not catch was that the clock had to increase every time it was a left operand, but never as a right operand. When A's clock is in a right operand (ex: {"B": x, "A": y}), a line must exists somewhere with {"A": y} on the left operand (and I guess this line would have to be a local event?). Before I understood, I was increasing A's clock every time I printed it. Now that I think back about my distributed computing class (featuring Michel Raynal!), I remember: when B receives a packet from A, A's clock must not increase (A's state doesn't change), because it already did when A sent the packet."

[Issue created by grahamstl: 2017-01-19]