Fix C# 3 compile errors.
Fix C# 3 compile errors.

BenJenkinson/nodatime,jskeet/nodatime,jskeet/nodatime,nodatime/nodatime,zaccharles/nodatime,nodatime/nodatime,zaccharles/nodatime,malcolmr/nodatime,malcolmr/nodatime,zaccharles/nodatime,BenJenkinson/nodatime,zaccharles/nodatime,malcolmr/nodatime,malcolmr/nodatime,zaccharles/nodatime,zaccharles/nodatime