This PR places all LMMS symbols into namespaces to eliminate any potential future name collisions between LMMS and third-party modules.
Also, this PR changes back `LmmsCore` to `Engine`, reverting c519921306 .
Co-authored-by: allejok96 <allejok96@gmail.com>
Add labeled controls for different types with a common base class
Implement a container for multiple equal groups of linked models and
suiting views. Such groups are suited for representing mono effects where each
Model occurs twice. A group provides Models for one mono processor and is
visually represented with a group box.
This concept is common for LADSPA and Lv2, and useful for any mono effect.
