rosie: installation guide update and some tidy up.

A result of multiple feedbacks by @hjoliver.

Fix #696. Fix #697. Fix #698. Fix #699. Should fix #700. Fix #701. Fix #702. Fix #703.

In addition:
* A new site/user configuration setting `[rosie-id]prefix-ws.PREFIX=URL` is introduced to
  configure the web service URL of each `PREFIX`.
  * The `[rosie-ws-client]ws-root-default=URL` site/user configuration setting is removed.
  * The `--ws-root=URL` option is removed from `rosie lookup` and `rosie ls`.
* `[rosie-browse]` in site/user configuration is now `[rosie-go]`.