Simplified PZH/PZH certificate exchange within the same provider.

When connecting to another personal zone hub within the same
provider, avoid having to reauthenticate.

Jira issue: WP-687
Minor fix: removing debug console.log entries from the sessionHandling code

Jira issue: WP-687
Merge pull request #453 from jplyle/WP-687-Simplify-PZH-Cert-Exchange

Simplified PZH/PZH certificate exchange within the same provider.