swarm: ctx propagation; bmt fixes; pss generic notification framework (#17150)

* cmd/swarm: minor cli flag text adjustments

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: update description of swarm cmd

* swarm: added network ID test

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* swarm: propagate ctx to internal apis (#754)

* swarm/metrics: collect disk measurements

* swarm/bmt: fix io.Writer interface

  * Write now tolerates arbitrary variable buffers
  * added variable buffer tests
  * Write loop and finalise optimisation
  * refactor / rename
  * add tests for empty input

* swarm/pss: (UPDATE) Generic notifications package (#744)

swarm/pss: Generic package for creating pss notification svcs

* swarm: Adding context to more functions

* swarm/api: change colour of landing page in templates

* swarm/api: change landing page to react to enter keypress

swarm/metrics/flags.go

@@ -81,6 +81,9 @@ func Setup(ctx *cli.Context) {
 			hosttag      = ctx.GlobalString(metricsInfluxDBHostTagFlag.Name)
 		)
 
+		// Start system runtime metrics collection
+		go gethmetrics.CollectProcessMetrics(2 * time.Second)
+
 		if enableExport {
 			log.Info("Enabling swarm metrics export to InfluxDB")
 			go influxdb.InfluxDBWithTags(gethmetrics.DefaultRegistry, 10*time.Second, endpoint, database, username, password, "swarm.", map[string]string{