Bluffline Inc. believes greenways can spur economic development and is bringing another Southern mayor to Pensacola to speak on how that’s possible. Knox White, mayor of Greenville, South Carolina, will speak Thursday night at “The Bluffline Presents: Mayor Knox White.” The Bluffline is a nonprofit group working to promote the creation of a series of greenways and trails to connect Pensacola along the waterfront from the University of West Florida campus to Bayou Chico. Last month, the group was announced a recipient for a $1.2 million grant from the U.S. Department of Transportation to study the waterfront trail concept……