InitRegCode
procedure InitRegCode (const Key : TKey; const RegStr : string; Expires : TDateTime; var Code : TCode);
InitRegCode creates and initializes a registration code using Key, RegStr, and Expires.
The code stores a hash value that was derived from RegStr. RegStr cannot be extracted from the code.
The resulting code is valid until the date stored in Expires is reached.
This routine is defined in the OnGuard unit. (as of 1.15 this routine has been moved to the OgUtil unit)