Fix OAuth and Realtime issues introduced in 9a515b9234
[DATABASE] Fix an empty default value mistake introduced in
fde929b151
[DATABASE][PostgreSQL] Avoid use of pg_constraint.consrc, which was removed in
PostgreSQL 12.
[DATABASE][MariaDB] Fix a typo introduced in aed2344bd4
[DAEMON] Wrap an assignment inside "switch":
a follow-up to adc689cb15
Avoid the use of deprecated MariaDB "zero dates" globally. If they're present
as attribute defaults somewhere, they will be replaced with NULL implicitly.
The existing "zero dates" in MariaDB storage will be left intact and this
should not present any issues.
The "timestamp" type in table definitions now corresponds to DATETIME in
MariaDB with "DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP", which
should be close enough to the original behaviour for compatibility purposes.
It is now the recommended type for "modified" attributes, because of the
update trigger on MariaDB. But there is no such trigger implemented on
PostgreSQL as of this moment.
lib/plugin.php now has a parent onAutoload function that finds most common
files that are used in plugins (actions, dataobjects, forms, libs etc.) if
they are put in the standardised directories ('actions', 'classes', 'forms',
'lib' and perhaps some others in the future).
