Update debugPtr to work with EPICS base 7.0.7

[simon-ess]

There are at least two changes to EPICS base since the addition of debugPtr:

• In pvAccess//dbdToPv.cpp, a write to an ostream was added (also in pvData//testSerialization.cpp) which does not resolve correctly when the operator<< overload is in the global namespace.
• In pvAccess/**/caChannel.cpp, weak_ptr->expired() was added

The interface to deal with each of these has been added.

Fixes https://github.com/epics-base/pvDataCPP/issues/88

[AppVeyorBot]

:white_check_mark: Build pvDataCPP 1.0.32 completed (commit https://github.com/epics-base/pvDataCPP/commit/f2f08ddd5b by @simon-ess)

[mdavidsaver]

Looks straightforward enough. Thanks!