refs #2174 some bugfixes

core/Site.php

plugins/CoreHome/CoreHome.php

...ins/CoreHome/javascripts/services/piwik-access-service.js

plugins/CoreHome/javascripts/services/piwik-api-service.js

...ns/CoreHome/javascripts/services/websitegroups-service.js

plugins/MultiSites/API.php

...s/multisites-dashboard/multisites-dashboard-controller.js

...ripts/multisites-dashboard/multisites-dashboard-filter.js

...cripts/multisites-dashboard/multisites-dashboard-model.js

...avascripts/multisites-dashboard/multisites-dashboard.html

.../javascripts/multisites-site/multisites-site-directive.js

...ltiSites/javascripts/multisites-site/multisites-site.html

plugins/SitesManager/API.php

plugins/UsersManager/API.php