Move the capabilities call out of api_controller

app/controllers/api/capabilities_controller.rb

@@ -0,0 +1,21 @@
+module Api
+  class CapabilitiesController < ApplicationController
+    skip_before_action :verify_authenticity_token
+    before_action :api_deny_access_handler
+
+    authorize_resource :class => false
+
+    around_action :api_call_handle_error, :api_call_timeout
+
+    # External apps that use the api are able to query the api to find out some
+    # parameters of the API. It currently returns:
+    # * minimum and maximum API versions that can be used.
+    # * maximum area that can be requested in a bbox request in square degrees
+    # * number of tracepoints that are returned in each tracepoints page
+    def show
+      @database_status = database_status
+      @api_status = api_status
+      @gpx_status = gpx_status
+    end
+  end
+end