Add a new method of interpreter objects, interpaddr(). This returns

Add a new method of interpreter objects, interpaddr().  This returns
the address of the Tcl interpreter object, as an integer.  Not very
useful for the Python programmer, but this can be called by another C
extension that needs to make calls into the Tcl/Tk C API and needs to
get the address of the Tcl interpreter object.  A simple cast of the
return value to (Tcl_Interp *) will do the trick now.