dot product operator

I was waiting for more feedback on this suggestion, but I'll go first since it's been a couple days. I can only speak for my own opinion, but in the OpenMx interface we've tried to add new operators when the R language was missing an operator. The Kronecker product and Kronecker exponent are two examples of this behavior (%x% and %^%). If the operator is already defined by the R language, I think it's preferable to train the users to use that definition. If the operator is already defined, and we define a new alias for the operator, the downside is that the alias only works in the OpenMx library. Users will need to learn the original definition when they use R outside of the OpenMx library.