MANITOU SPRINGS - How are you spending your summer vacation? No doubt you will have more fun and relaxation than Diane Fitzkee. Her summer break from teaching blind children in the Falcon School District is shaping up like a disaster. She is bunking with friends while she salvages what's left of her beloved 135-year-old cottage before having it demolished and rebuilt. Worse, the experience likely will force her to delay retiring in a few years because of the strain on her finances. The wrecking crew is coming, even though she absolutely loves the little white house with the maroon trim and white picket fence. It doesn't matter that she may lose the flagstone patio she installed.