Bump version 2.5.3
Bump version 2.5.3

zanker/protobuf,brianstien/protobuf,localshred/protobuf,lookout/protobuffy,film42/protobuf,ruby-protobuf/protobuf,brianstien/protobuf,film42/protobuf,zanker/protobuf,quixoten/protobuf,localshred/protobuf,lookout/protobuffy,ruby-protobuf/protobuf,quixoten/protobuf