Issue #69 - Removed min_val and replaced it with LEAST (see PostgreSQL docs). I've adde pg_notify for channel ch_order_completed in trigger procedure for order updates. I've also removed pg_notify for channels ch_zlecenie_kupna and ch_zlecenie_sprzedazy. I've added two pg_notify for channel ch_order_change in procedure przenies_dobra.
Merge branch 'ConcurrentServer-prototype-1' of https://github.com/jam231/sia2013 into ConcurrentServer-prototype-1