Changes in ProtoBuf.js 3.8

It has been requested to change the default representation of binary data when converting binary fields to JSON-like objects and vice-versa.

As of version 3.8.0, ProtoBuf.js uses base64 encoding by default:

• Instead of returning buffers, Message#toRaw([includeBinaryAsBase64=false]) now returns base64 encoded strings for binary data when includeBinaryAsBase64 is set to true (was: includeBuffers).

• String assignments to bytes fields by default parse the string as base64.