Proto commits in pajowu/signal-backup-decode

These 3 commits are when the Protocol Buffers files have changed:

Commit:14ed513
Author:pajowu

Update protobuf, implement new fields & frames as noops

The documentation is generated from this commit.

Commit:87f4a2e
Author:pajowu

Add support for stickers

Commit:726db82
Author:pajowu

Initial Commit