When auditioning, ardour's process_audition calls Route::silence
for all routes. PluginInsert::silence simply fed all [ports of all
[replicated] plugins with silence, regardless of port-mapping.
This can cause some VST2/3 plugins to change state, and enable ports
(e.g. stereo VST2 plugins on mono tracks), causing glitches.
This commit is mainly intended to investigate how significant
this glitch is when starting to audition.
b3497b3f8f