Digital video manager Blackwave has closed a $7 million third round as it works to add improvements to its technology and build up its marketing efforts. The Acton, Mass.-based company has raised more than $29 million since opening its doors in 2006. This latest investment comes from existing backers, Globespan Capital Partners, Flybridge Capital Partners and Sigma Partners. The company has so far been able to benefit from the proliferation of online video companies. Earlier this year, Blackwave began offering content distribution services as well as a video production platform. Release