Make the configuration penalty subtler about inputs
Instead of uniformly demote configurations with a non-matching audio
input count (using a penalty offset of 1000), also grade the
impreciseness of the configuration so that those with the nearest input
count are preferred. As for outputs, give a slightly higher handicap to
configuration with too many inputs with regard to the actual audio
inputs that can be fed to the plugin.
POLICY CHANGE: when only imprecise configurations are found the actually
selected one can be different (better) than before this commit.