Render the output in shutdown handler was causing
issues in phpunit test_psr_classloader
This is an small fix to check that the output has been started.
* all constans usable in ABORT_AFTER_CONFIG should be always defined
* MDL_PERFDB and $PERF->logwrites not used after legacy log removal
* MDL_PERF_TEST should be documented in codebase
* deprecated warnings in shutdowb manager
The PHP_CodeSniffer @codingStandardsIgnore annotations are deprecated
and, since version 3.x, the new // phpcs:ignore comments should be used
instead.
This commits just reviews all the uses in core, replacing them for
the better new candidate, or removing when no longer needed.
raortegar