fix warnings -Wdeprecated-copy

[mathieugouin]

As discussed in #18

if someone has some time, and a good knowledge of over-riding
C+ operators and copy constructors, i am interested to get advice
on  most recent change on the development branch:
"fix warnings -Wdeprecated-copy"

that patch avoids the warning by avoiding the offending custom
copy constructor entirely, by requiring clients to create their
own object, and pass a pointer into the offending methods instead
- so now, the custom copy constructor is not used at all; but it
does something clever (convoluted), which a default copy would
not - that indicates a smell, either in the original code (maybe
the custom copy constructor was never needed), or in a new bug
being introduced now (maybe it is needed in some cases; but now
it's special handling wont happen) - i have not had the bandwidth
to dig into it deeper; but i suspect that there is a less
intrusive way to fix that compiler warning

[bill-auger]

i tried it earlier - the current change is not good - it throws many errors; so probably it broke the configuration system