Add remaining get_backdoor_port() rpc calls to coverage.

This adds the get_backdoor_port() rpc calls for cert, conductor,
console, consoleauth, and scheduler so that the coverage
extension can now telnet into all of those services.

Change-Id: I5de654a11ac224b1192a3b1601855c302b771efd
Clarify & fix docs for nova-novncproxy

Clarify docs for nova-novncproxy to indicate that it only serves
noVNC web content. Also remove duplicated link from manpage

Change-Id: Ia1f4aff21591132a5c41810a371d248ea0001e1f
Merge "Add remaining get_backdoor_port() rpc calls to coverage."
Merge "Clarify & fix docs for nova-novncproxy"