grb::set matrix-to-matrix broken in mixed-domain

[byjtew]

The primitive grb::set( Matrix<D>&, const Matrix<T> ) contains a bug related to the cast of the values from T to D.

[anyzelman]

Hi @byjtew -- I don't recall we merged into develop, but #654 does say it is merged-- what happened here?

[byjtew]

Hi @byjtew -- I don't recall we merged into develop, but #654 does say it is merged-- what happened here?

I am pretty sure I force-pushed incorrectly and erased my commits. I managed to find a previous version, it's in a new PR.