It turns out that slightly older versions of ALSA create different "pretty"
port names for USB MIDI devices than slightly newer ones. The new versions
use names that match those seen on other platforms.
This means that to do port matching on Linux now requires a regexp
to match the possible alternatives. This matters much more for the LPP,
which has 3 input ports and 3 output ports, than it does for most devices
that have a single input and single output, and we can "find" the ports
just using simple string searching
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.
libardourcp and now libardour_midisurface are not control
surfaces, but helper libraries for those.
They need to be deployed to the library folder (shared between
ctrl surfaces) and not scanned as ctrl surfaces at runtime.
