event_system:
                draft implementation of	repeated events	(we still have none defined by protcol)
                more appropriate names for some	enums and structs
        messaging:
                a bit of refactoring in	server_session (cut message handler to separate functions for each message type)
                more appropriate names for some functions
        curl_downloader:
                updating downloaded size variable during download process (thread safety required)

	download completed state
client-qt:
	added "download completed" subscription and status support
server:
	module_curl:
		used events api in core for download state changes
	core:
		download completed event support for modules

	very basic implementation of download_state_changed event api call for plugins
	started work on thread safety (plugins may and will be multithreaded, so api for plugins should be thread safe)

updated copyrights (new year)
server:
	started implementation of api for module events (module should be able to fire event which will be delivered to clients which have subscribed for this event type)

	added subscription to download deleted event (handler not implemented yet)
server:
	simplified "fire _event" implementation
	basic implementation of "add_event_subscription" in client class

	added download_state change structure (used in download state changes event
from server)
client-qt:
	subscription to download state changes events
server:
	basic implementation of download state changes events

TODO: use single structure for download_state_changes in messages instead of all
separate ones.

	a bit of work with event system

	tiny enum value names correction
server:
	event subscription subsystem:
		a bit of implementation of repeated event type

	a bit of work with "client_event_subscription_request"
	some comments
server:
	event subsystem:
		event's object class skeleton
		very basic event subscription handler

	api:
		added std::list<std::string> metadata_setting_list(const std::string &module_name) to get list of all saved settings/metadata entries
	flat_files_metadata_module:
		implemented new metadata api call
	curl_downloader_module:
		reimplemented startup metadaats loading, still bad ...