on 64bit architectures, xdr_long silently truncates 64bit values to 32bit or 0

I just noticed that `xdr_long` and family can't encode 64bit values but truncates them to 0 and reports error if it can't represent the value in 32 bits.

I didn't find any usage of NML message containing long ints, but IMO those cms::update functions with long family should be removed so nobody needs to walk into that trap again. 