* 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
Merge with changes that implement config file PR #15548.
Field *EnsApi string* in swarm/api.Config is replaced with
*EnsAPIs []string*.
A new field *EnsDisabled bool* is added to swarm/api.Config for
easy way to disable ENS resolving with config file.
Signature of function swarm.NewSwarm is changed and simplified.
