THE CITY-OWNED lot, neighbors say, was in deplorable shape, thick with weeds and trash. So when a business owner cleaned it up last month, spending more than $20,000 and removing, by his count, more than 40 tons of debris, Point Breeze residents went out of their way to pass 20th and Annin streets to see the changes. "This was a lot of garbage," Elaine McGrath said as she took in the carefully tended plantings and wooden benches. "Now it's gorgeous. I'm excited." But not everyone is happy with the alterations - namely, the lot's owner, the Philadelphia Redevelopment Authority.