[Dlang-internal] Removing ddmd. prefix from dmd module names

[Walter Bright via Dlang-internal]

On 11/28/2016 1:43 AM, Dicebot wrote:
> Still it would be nice to get your preference/approval for some of dmd
> package models proposed here - it will come up again anyway.

I know. But I am unsure what the right arrangement is. At least this switch 
converts the problem from a crisis to an annoyance.