{CVS ci] alternate object initializer calling scheme

[Leopold Toetsch]

I've put in the new scheme for initializer calls.
To test it, set the environment variable "CALL__BUILD" to some value.
Sample code to set an initializer to "_new"

    new P10, .PerlString
    set P10, "_new"
    newclass P1, "Foo"
    setprop P1, "BUILD", P10
The BUILD initializer is called for all parents as "__init" was. There 
is additionally a "CONSTRUCT" initializer, which is only called for the 
top-level class.

The instantiation "new Pobj, Iclass" can now take an additional 
initializer too:

   new Pobj, Iclass, PInit

This initializer is available as first param in the init method.

Comments welcome,
leo