The Dallas Museum of Art did something big: They handed the main gallery — not just a wing, but the whole damn thing — over to local artists for the new show Dallasites: Available Space. They stepped up. The DMA had faith in the quality of local art, artists and curators selected and gave North Texas its own month-long show. That means thousands of museum-goers will see what’s being made right here, for free. And guess what? Available Space is worth the real estate.