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>
Implement `LV2_OPTIONS__options` feature and some buf-size properties.
The code currently assumes that the LMMS buffersize never changes, which
is currently true in the LMMS code base.