Latest protobuf.js requires that we pass in the sign value when making
longs from strings, ex: dcodeIO.Long.fromString(id, true);
However, it does the string->long conversion automatically if its given
a string for a fixed64 field, so we can pass our string ids right in!
ftw
Parse attachment ids out of the attachment pointer url and return them
as strings because the copy parsed by JSON suffers a loss of precision.
Convert them to and from the format expected by the protobuf using
facilities from decodeIO.Long.
DRY up protobuf declarations and move to a slightly briefer naming
convention.
Also dropped some ArrayBuffer -> string conversions as
ProtoBuf.js handles ArrayBuffers just fine, and in fact, more
efficiently than strings.
Finally, dropped the btoa() wrappers, because that incurs an extra
string -> string conversion before the protobuf's internal string ->
array buffer conversion. In lieu of btoa, we can simply pass in the
optional string encoding argument to the protobuf's decode method,
which in these cases should be 'binary'.
Related: #17
All the group messages were being sent to the last recipient in the
list, due to the persistence of `var number` in later loops and async
calls. An easy mistake to make, when you use for instead of each.
