chore: add remove-signer command, fix bugs, and update release notes

- Add registry admin remove-signer command to remove a signer and all their authorizations
- Fix remove_package_signer condition (is_some -> is_none) for correct not-found error
- Use log_err() instead of silently swallowing asset fetch errors
- Trim leading '#' from version in s9pk publish path
- Add --delete-removed to s3 sync in publish-deb.sh
- Expand v0.4.0 release notes with additional features
- Regenerate man pages and add i18n entries

core/man/start-container/start-container.1

@@ -1,6 +1,6 @@
 .ie \n(.g .ds Aq \(aq
 .el .ds Aq '
-.TH start-container 1  "start-container 0.4.0-alpha.21" 
+.TH start-container 1  "start-container 0.4.0-beta.0" 
 .SH NAME
 start\-container
 .SH SYNOPSIS
@@ -34,6 +34,8 @@ start\-container\-get\-status(1)
 .TP
 start\-container\-git\-info(1)
 .TP
+start\-container\-pipe\-wrap(1)
+.TP
 start\-container\-plugin(1)
 .TP
 start\-container\-rebuild(1)
@@ -50,4 +52,4 @@ start\-container\-shutdown(1)
 .TP
 start\-container\-subcontainer(1)
 .SH VERSION
-v0.4.0\-alpha.21
+v0.4.0\-beta.0