Merge pull request #8065 from piwik/6061

core/Plugin/MetadataLoader.php

plugins/Contents/lang/en.json

plugins/Contents/plugin.json

plugins/CorePluginsAdmin/Controller.php

plugins/CustomVariables/CustomVariables.php

plugins/CustomVariables/lang/en.json

plugins/DevicesDetection/DevicesDetection.php

plugins/DevicesDetection/plugin.json

plugins/Ecommerce/lang/en.json

plugins/Ecommerce/plugin.json

plugins/Events/lang/en.json

plugins/Events/plugin.json

plugins/ImageGraph/Controller.php

plugins/ImageGraph/ImageGraph.php

plugins/Insights/lang/en.json

plugins/Insights/plugin.json

plugins/LeftMenu/lang/en.json

plugins/LeftMenu/plugin.json

plugins/MultiSites/MultiSites.php

plugins/MultiSites/plugin.json