Fixed the path to json2.min.js & innersvg.js in chart.twig (were relatives links instead of full url)
Merge branch 'hotfix/IE7_rendering' into develop
refactored chart publication code into Chart model
redirecting old chart urls to most recent version
redirecting from unversioned url, too
strict testing for null
updated localized messages
added cronjob hooks
added schema and object models for new plugin_data table
updated db migration script
turning id into auto-incrementing integer
added convenient plugin API for reading, storing and deleting data
Merge branch 'feature/plugin-data' into develop
updated changelog
Merge branch 'develop' into new_way_for_collcetion_chart_assets

Conflicts:
	lib/utils/chart_publish.php