(grant of partial summary judgment to respondent affirmed - contribution of facade easement did not comply with the enforceability-in-perpetuity requirements of Treas. Reg. Sec. 1.170A-14(g)(6); cash payments to charity that accepted facade easement remained conditional at end of 2003 and are not deductible, but cash payments made in 2004 are deductible; facade easement not protected in perpetuity because donee organization not guaranteed proportionate share of proceeds in event of casualty or condemnation as required by Treas. Reg. Sec. 1.170A-14(g)(6)(ii); accuracy-related penalty applicable for deduction of cash payments in 2003).