Leaders have lagged the market as of late. But they outperformed during last week's short trading week. Thanks to big gains in several top stocks, the IBD 50 climbed 0.6% for the week vs. a 0.2% gain for the S&P 500. The Nasdaq fell 0.2%. CommVault Systems (CVLT) blasted up 23% for week, putting it back above its 10-week line and a 53.90 buy point. The maker of storage software surged on better-than-expected fiscal Q2 2013 results. Its earnings