This is mostly a simple lexical search+replace but the absence of operator< for
std::weak_ptr<T> leads to some complications, particularly with Evoral::Sequence
and ExportPortChannel.
In some cases old and/or conflicting port names were saved
with the session (e.g. "Faderport" for FP1,8). Loading old sessions
then merges this state into the config, which could lead to
port-registration failure when the surfaces was enabled.
