[VEX] get attrib VEX function

getattrib()
<type>   getattrib(<geometry>geometry, string attribclass, string attribute_name, int elemnum, int &success)
<type>[] getattrib(<geometry>geometry, string attribclass, string attribute_name, int elemnum, int &success)

e.g.)
int success;
v@accel = getattrib(1, "point", "accel", opdigits(s@name), success);
--
attribclass
One of "detail" (or "global"), "point", "prim", or "vertex".
You can also use "primgroup", "pointgroup" or "vertexgroup" to read from groups.