MIDEAST STOCKS-Oil rally boosts Saudi, property shares support UAE

* Saudi petchems lead market up * Emaar, The Economic City jumps on sovereign fund interest * Property shares support Dubai, Abu Dhabi before exhibition * Dubai's volume at four-month high * Shuaa Capital surges daily limit By Celine Aswad DUBAI, Sept 5 (Reuters) - Saudi Arabia's stock market posted its biggest daily gain in four months on Monday as oil prices surged, while shares of Dubai's property developers rose before a major exhibition for the industry this week. Riyadh's stock index rose