Fix vsay configuration.

This was using numbers for class and team, which is bad: various class
numbers have been changed and this file had become out of sync. Now, we use
team names and class names (from the models); class removals could cause
parse failures, indicating that the vsays file need an update.

"team" requires "aliens" and/or "humans".

"class" requires class model names, "aliens", "humans" and/or "all". These
latter three select, respectively, all alien classes, all human classes and
all classes. It's also possible to remove from the class list by preceding
with "-" (outside quotation marks): this affects the next token only, e.g.
  class aliens -basilisk -"advanced basilisk"
for all alien classes except the basilisk forms.