list append syntax for postgresql.conf

Nowadays there are a number of methods for composing multiple
postgresql.conf files for modularity.  But if you have a bunch of things
you want to load via shared_preload_libraries, you have to put them all
in one setting.  How about some kind of syntax for appending something
to a list, like

    shared_preload_libraries += 'pg_stat_statements'

Thoughts?

-- 
Peter Eisentraut              http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services