The previous changes in the interface were to drastic. They would have
required too many changes for a service that is likely to be rewritten
for ROOT7 within the next 2 years anyway. (2018, 2019)

So here we offer a deprecated version without proper ownership
management that still works the same in the new implementation.

Fix wrong naming in ITHistSvcMT

Update ITHistSvc for better legacy support

There is now a deprecated regHist method with the old interface.
Since we don't want to spam too much during the Athena build, the new
regHist method, that transfers ownership, can also return a raw pointer
directly. This supports a very common use case in Athena, where the
registered histogram is used afterwards.
The migration is likely to be scriptable in this case.

Adapt new interface in THistSvc.h

Fix small typo in THistSvc.h

Update InterfaceID version in ITHistSvc

Fix wrong default parameter in interface

Fit implementation to new interface

Fix THistSvc tests and ref files

Remove TODOs that are not relevant yet

Apply formatting from CI artifacts

Update IHistSvc to be more consistent

Add THistSvc tests and fix reference

The write tests now also contains tests for the new regHist and
regShared/getShared methods.

Update dbg reference as well

Apply formatting patch

Remove deprecation attribute from ITHistSvc

This would introduce an additional warning for every Gaudi build, while
the intention is to discourage the use of its implementation in
THistSvc.h.
The interface method is still marked as deprecated through a doxygen
comment.

Add accidentally deleated return type to regHist

Comment out deprecation attribute in THistSvc.h

Initialize pointer in THistSvc tests

Add GAUDI_API back to ITHistSvc

Initialize all pointers in THistSvc

Apply clang formatting patch from CI

Hide deprecation warning behind ATLAS includeguard

Let the thistwrite ignore specific file sizes

Revert sortgroup regex

The previous change did not cover all of the necessary cases and was
wrong.

Apply formatting artifacts

Change test regex also for reading