block_base->config_save is not used anywhere any more. If contributed plugins
rely on it, it makes no difference since it is not being called, if they do
something like $this->config_save or parent::config_save somewhere in their
block class instance, this will still work as deprecated function will handle
it.
This patch includes:
* version column removed from modules table, now using standard config, this allows decimal version for modules
* version column removed from block table, now using standard config, this allows decimal version for blocks
* module version.php can safely use $plugins instead of module
* new plugin_manager bulk caching, this should help with MUC performance when logged in as admin
* all missing plugins are now in plugin overview (previously only blocks and modules)
* simplified code and improved coding style
* reworked plugin_manager unit tests - now using real plugins instead of mocks
* unit tests now fail if any plugin does not contain proper version.php file
* allow uninstall of deleted filters
