Ensure that the guest user is in the database when upgrading accounts

Feature: Purge local room history.

Add an admin option to shared secret registration (breaks backwards compat)

Follow up to adding password pepper

Signed-off-by: Kent Shikama <kent@kentshikama.com>

Signed-off-by: Kent Shikama <kent@kentshikama.com>

requestToken update

Use a query that postgresql optimises better for get_events_around

Add pepper to password hashing

Use true/false for boolean parameter inclusive to avoid potential for sqli, and possibly make the code clearer

Signed-off-by: Kent Shikama <kent@kentshikama.com>