add all()

[dangmoody]

Useful helper function, definitely faster than comparing against a bool vector/matrix constructor of all true. Should definitely go in.

Basically should just look like this:

bool all( const bool2& x ) {
    return x.x && x.y;
}

// and so on for bool3, bool4, bool3x2, etc.

[dangmoody]

The implementation is in the repo. Will mark as done and close when it's actually in a release.

[dangmoody]

Dropping the whole "close when the release is out idea". This will come out in the next release.