By Alvaro Murillo SAN JOSE (Reuters) -German entrepreneur Rainer Schaller, known for his line of fitness studios, was among the passengers on a plane believed to have crashed in Costa Rica, authorities from the Central American country said on Saturday. Costa Rican authorities said they found wreckage earlier Saturday about 17 miles (28 km) from Limon airport believed to be from a private plane carrying Schaller, the founder of Germany’s McFit gym chain, and some members of his family. Schaller, 53, was traveling with other Germans including a 44-year-old woman, a 40-year-old man and two minor…
