Fix a use after free in IrcChannel::remove_user

Fix a missing include for strlen

Properly calculate the maximum size of each message line, before cutting

fix #3067

Save our own host, as reported by the server

cut messages at 512 bytes, taking into account the UTF-8 codepoints

ref #3067

Add get_next_codepoint_size

Refactor, test and improve the way we cut too-long messages for IRC

Add a missing return bool in Config

Fix a doc typo

Improve the signal handling by disabling them while an handler is running

Clean the Config module, use static things instead of a stupid singleton

Make the logger tests more useful

Show off, with some variadic templates, for the logger module

Display a message to tell if we found pandoc or not

fix #3177

Make the default config file put the database in /var/lib

Allow cmake to configure the systemd unit’s user and group

Reset the preferred private JID when all resources leave a room

For example if we are talking in private with nick Joe from
room #foo, and then we leave that room, we start receiving Joe’s
message from the server-wide JID

e2e tests included!!!

Add some e2e tests to check that private messages come from the right JIDs

Add a basic e2e test for channel and private messages

Add a missing vector include