Chandigarh, Aug. 12 -- The Punjab Vigilance Bureau (VB) has given a clean chit to three retired IAS officers, including former chief secretary Sarvesh Kaushal, in the multi-crore irrigation scam after a detailed inquiry failed to find concrete evidence substantiating allegations against them.Names of former special chief secretary KBS Sidhu and ex-irrigation secretary Kahan Singh Pannu have also been cleared. P2...