PLEASE backup your database before testing this commit, and report any
migration issue.

In postgresql, we use timestamp with timezone.
In sqlite3 we use REAL (the date is expressed as julianday)

This requires a migration of the muclogline_ table:
In postgresql it’s pretty simple, we convert all the integer into timestamps

With sqlite3, we actually rename the table, create the new one with the
correct type, then copy everything to the new table, with a conversion
function for the Date_ column, and then we delete the old table.

fix #3343

fix #3317

Otherwise we can imagine that two clients changing this value at the same
time would mix things up.

ref #3275

fix #3275

This reverts commit ba879a88.

ref #3273

fix #3273

fix #3293

By using SFINAE to use that member only when it exists.

ref #3269

Entirely replace LiteSQL

fix #3271

This makes us compatible with mam 6.0

fix #3249

Instead of doing a broken SQL request that returns weird lines

Do not use a singleton for the database.

fix #3203

It’s $CURRENT_YEAR

Move all constructors at the top of classes

And a way to retrieve its values, defaulting on the ServerOptions for unset
values.

Uses litesql