Jive does not support full range of DevULong64 values

Created by: t-b

Tango 9.2.5a and TangoTest device

In Jive i can not set ulong64_scalar to values like 2^64 - 1. The largest value I can set is 2^63-1. Additionally values like -1 are accepted where as ulong_scalar does not accept negative values.