better error message if we webfinger a person with invalid guid

this happens if a remote person changed the diaspora-id manually (renamed
domain or something) in their database.

Set the default limit of dead jobs to 5k, which should equal to about 50M memory
usage in the worst case. Sidekiq's default is 10k. Set the expiration
timeout to 6 weeks, matching our minor release schedule. Sidekiq's
default is 6 months.

Given the new federation code stores the XML payload in the job
parameters, fine-tuning here can give more significant memory savings.

Refactored photo extraction

style improvements

new line

applied changes

applied changes

Add 'Be excellent to each other!' to the sidebar

 [Fix] #6850 Don't include subjects of private message

Cleanup StatusMessage

this didn't do anything

all data is included in the federated status_message, so we can validate
on receive. add the photos to the status_message before save.

This was only an alias for "text", and "raw_message" is also not used
for federation anymore, so we can drop it.

bump diaspora_federation gem

Fix randomly failing profile federation spec

Improve coverage

Remove messagebus_ruby_api gem

Remove unused methods

Messagebus closed in 2015. See https://web.archive.org/web/20150623093956/https://www.messagebus.com/ for more information.

Filter mentions on status message creation

* Fix issue #6847

Remove unused translations from diaspora.yml, add missing ones