Add a view command (primarily)

The view(2-4) command switches viewpoint to the desired player--by number, by full, case-insensitive name, and by abbreviated case-sensitive name (in order of preference).

Included here also is promotion of viewpoints. That is, when requesting to view a player on viewpoint four and only one viewpoint is already present, viewpoints two through three are also switched--to someone different than four.

These two changes sort of got mixed together.