There is a new theme property 'blockrendermethod' that can be set by the
theme in its config.php and tells Moodle what method it is using to render
blocks in the layout files.
Either blocks, or blocks_for_region.
Then when adding custom block regions to a page content we ensure we use
the same method the theme is using elsewhere.
This is really a hack becuase we (I) didn't properly deprecate
blocks_for_region when I added the blocks method.
On edit quiz page marks/reorder text box has zindex set, which should be considered by modal
window. Also, tab set is also using zindex for active node.
This patch prevents inclusion of settings from plugin that or not yet installed or upgraded,
this matches the original logic where we were using the modules table.
List of changes:
* New OOP API using PHP namespace \core\session\.
* All handlers now update the sessions table consistently.
* Experimental DB session support in Oracle.
* Full support for session file handler (filesystem locking required).
* New option for alternative session directory.
* Official memcached session handler support.
* Workaround for memcached version with non-functional gc.
* Improved security - forced session id regeneration.
* Improved compatibility with recent PHP releases.
* Fixed borked CSS during install in debug mode.
* Switched to file based sessions in new installs.
* DB session setting disappears if DB does not support sessions.
* DB session setting disappears if session handler specified in config.php.
* Fast purging of sessions used in request only.
* No legacy distinction - file, database and memcached support the same functionality.
* Session handler name included in performance info.
* Fixed user_loggedin and user_loggedout event triggering.
* Other minor bugfixing and improvements.
* Fixed database session segfault if MUC disposed before $DB.
Limitations:
* Session access time is now updated right after session start.
* Support for $CFG->sessionlockloggedinonly was removed.
* First request does not update userid in sessions table.
* The timeouts may break badly if server hosting forces PHP.ini session settings.
* The session GC is a lot slower, we do not rely on external session timeouts.
* There cannot be any hooks triggered at the session write time.
* File and memcached handlers do not support session lock acquire timeouts.
* Some low level PHP session functions can not be used directly in Moodle code.
heading(), change the default value for classes from 'main' to null.
heading_with_help(), add 2 additional parameters for level and classnames. Default value of level is set to 2 and classnames is set to null.
With the changes for heading_with_help(), icon image vertical alignment needs to be adjusted, so it display in the middle of the heading.
Also added some notes in theme/upgrade.txt file.
