Person.find_or_fetch_by_identifier raises an exception if person is not found localy and not fetchable. It never returns nil. These code changes take care about this behaviour and changes specs and code to behave equally.

Also related to #8253

closes #8268

Using galleries default border radius Small indicator images in image gallery are round ones, this doesn't correspond with preview shown in stream. It also doesn't look good on real-world images. (may look OK for User profile images)

closes #8275

closes #8276

closes #8267

This reverts b3ca504c. We don't quite know why that was added, but we assume it's because of format strings. Some pre-2011 users exist that still have dots or dashes in their username, and those accounts are somewhat broken now.

closes #8266

The chat is already removed for 0.8, so there is no need to still export
this data since it can't be imported anyway.

Related to #8069

closes #8265

closes #8263

Gem updates

closes #8262