Maintain separate registries for clients and servers connections

[shroffk]

@mdavidsaver

[mdavidsaver]

https://github.com/epics-base/pvAccessCPP/blob/master/src/client/pv/pvAccess.h#L1322

What is being referred are replacement of the one singleton ChannelProviderRegistry with two access through: ChannelProviderRegistry::clients() and ChannelProviderRegistry::servers().

[mdavidsaver]

As I think about it, there was a related change to ChannelProviderRegistry to allow providers to be created with a specific Configuration.

https://github.com/epics-base/pvAccessCPP/blob/master/src/server/pv/serverContext.h#L120

Also, servers can now be created directly with ChannelProvider instance(s) instead of going through the registry/factory process. I found this more natural as all existing server providers are really singletons where the factory concept only gets in the way.

[ralphlange]

Copied to its new home.
Closing.