am-hook: Fix missing return

Update CHANGELOG

am-hook: Add version indicator

go fmt

Complete initial alertmanager hook

Add CHANGELOG

Note that clients are safe for concurrent use

Document allowed file types

tcli: Implement sending images

Implement SendImage

Update README

Ignore profiling files

Implement support for other message types

tcli: Fix grammar

tcli: Document the qr command

Return raw bytes when hashing phone numbers

It is up to the caller to encode the result if necessary

Use hex.EncodeToString where appropriate

tcli: Add qr command to display client's qr code

Add ID() and PublicKey() methods

Add documentation for tcli package