refs #1820 metrics picker, refs #1454 using Api.get for cross-plugin evolution graphs

core/Controller.php

core/ViewDataTable/GenerateGraphData/ChartEvolution.php

core/Visualization/Chart.php

core/Visualization/Chart/Evolution.php

lang/de.php

lang/en.php

libs/jqplot/plugins/jqplot.canvasAxisTickRenderer.js

plugins/API/API.php

plugins/Actions/API.php

plugins/Actions/Actions.php

plugins/CoreHome/templates/graph.tpl

plugins/CoreHome/templates/jqplot.css

plugins/CoreHome/templates/jqplot.js

plugins/CoreHome/templates/sparkline.js

plugins/VisitsSummary/API.php

plugins/VisitsSummary/Controller.php

plugins/VisitsSummary/VisitsSummary.php

tests/integration/Main.test.php

...ted/test_ecommerceOrderWithItems_API_get__API.get_day.xml

...ed/test_ecommerceOrderWithItems_API_get__API.get_week.xml