Explicitly import underscore, remove redundant jslint/global directives

...ntend_client/app/admin/databases/databases.controllers.js

.../app/admin/metadata/components/MetadataTableList.react.js

...rontend_client/app/admin/metadata/metadata.controllers.js

...ent/app/admin/settings/components/SettingsEditor.react.js

...nt/app/admin/settings/components/SettingsSetting.react.js

...rontend_client/app/admin/settings/settings.controllers.js

resources/frontend_client/app/app.js

resources/frontend_client/app/auth/auth.controllers.js

resources/frontend_client/app/card/card.charting.js

resources/frontend_client/app/card/card.controllers.js

resources/frontend_client/app/card/card.services.js

...rces/frontend_client/app/components/ActionButton.react.js

resources/frontend_client/app/controllers.js

resources/frontend_client/app/dashboard/actions.js

...nd_client/app/dashboard/components/DashboardGrid.react.js

resources/frontend_client/app/dashboard/selectors.js

resources/frontend_client/app/directives.js

resources/frontend_client/app/explore/explore.services.js

resources/frontend_client/app/forms.js

resources/frontend_client/app/js/google_maps.js