Update libgphoto2.pc to require both libgphoto2_port >= 0.6.2 and libexif >= 0.6.13
Update libgphoto2.pc to require both libgphoto2_port >= 0.6.2 and libexif >= 0.6.13

git-svn-id: 40dd595c6684d839db675001a64203a1457e7319@9230 67ed7778-7388-44ab-90cf-0a291f65f57c

gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION,gphoto/libgphoto2.OLDMIGRATION