Increase connection timeout and improve status for initialization

[krassowski]

References

Fixes #468

Code changes

• Retries checking if connection is initialized:
  • every 150ms for 30 seconds first and if does not get there emit an early warning, and then
  • every 1 second for 5 minutes
• Actually check if servers are installed and only say that they are missing if they are not installed and not if they are unable to be reached

User-facing changes

In addition to above changed "Partially initialized" label to "Initializing..." to better reflect the underlying status, and to help distinguish new problems from old problems ;)

Backwards-incompatible changes

None

Chores

• linted
• tested
• documented
• changelog entry