Remove some redundancy from the DValue hierarchy: all subclasses had a 'type' field and identical implementations of virtual function getType(). Move these to DValue itself, and make getType() non-virtual.

module typeinfos2;

import
typeinfo2.ti_AC,
typeinfo2.ti_Adouble,
typeinfo2.ti_Afloat,
typeinfo2.ti_Ag,
typeinfo2.ti_Aint,
typeinfo2.ti_Along,
typeinfo2.ti_Areal,
typeinfo2.ti_Ashort,
typeinfo2.ti_C;