Dashboard links

Hi,

This is a small ux improvement to the management dashboard. I was instinctively trying to click on the applications and sources listed on the overview page. This was partly because the text turned blue on hover and also it seems natural that these should be clickable. 

This pr makes the listed applications and sources clickable and disables changing text color on section hover, unless hovering over a link.
Good addition but maybe we move this case logic into a helper:

          %li
            = dashboard_link_for(resource, item)

And then have ha helper something like: 

module DashboardLinkHelper
  def dashboard_link_for(resource, item)
    case resource
      when "Application"
        link_to item.name, app_path(item.id)
      when "Source"
        link_to item.name, item.uri, target: '_blank'
      else
        item.name
    end
  end
end