The actual loading of available updates info objects is moved back to
the plugin manager class. As we can now mockup the manager in unit
tests, this allows us to bypass the real \core\update\checker and have
unit tests for \core\plugininfo\base::available_updates().
Plugin info objects are owned by the plugin manager (composition
pattern). Even if the plugin manager is a singleton, we need to keep
explicit reference to the plugin manager that owns the plugin info so
that we can mock up things in unit tests.
Therefore this patch introduces a new property of plugin info objects
that holds the reference to the instance of the plugin manager that made
(and hence owns) the given info instance.
The only trouble here is with static methods of plugin info classes such
as \core\plugininfo\base::get_enabled_plugins(). In these cases, the
code keeps using the core_plugin_manager singleton. The solution would
be to pass the plugin manager instance as a parameter but that is not
worth of change for now, IMHO.
Before this patch, whenever core_plugin_manager::get_plugins() was
called, it always attached info about available updates. But this is
needed only in quite rare cases, such as when the admin is looking at
the Plugins overview and Plugins check screens. There is no need to load
this on other places and for non-admin users.
The patch removes the loading from the method
core_plugin_manager::get_plugins_of_type() and implements lazy loading
directly in the plugininfo classes so that it is loaded only when
\core\plugininfo\base::available_updates() is actually called.
Includes:
* update checker refactored to \core\update\ namespace
* plugininfo classes refactored to \core\plugininfo\ namespace
* plugin_manager renamed to core_plugin_manager
* redirect back to original page after plugin uninstall
* fixed assign subplugin uninstall
* move assign subplugins under the assignment in admin tree
* fixed plugininfo for all question related plugin types
* auth uninstall support
* added missing block dependencies
* added theme uninstall
* subplugin types are following the plugin on plugin overview page
* several performance improvements in plugin manager
* new warnigns when plugininfo are outdated or missing
* multiple fixes and other improvements
