List more helpful suggestions than check username and password for database issues

[ralatalo]

During initial setup, if wordpress can't connect to the database it only suggests checking username, password and host and checking if your database is running. I have already filed enhancement request #65034 to increase the diagnostics but this request is to add additional suggestions:
Currently you suggest:
'Are you sure you have the correct username and password?'
'Are you sure you have typed the correct hostname?'
'Are you sure the database server is running?'
I would suggest adding:
'You may also need to check for possible Firewalls'
'You may also need to check for possible security restrictions such as SELinux'

Possible a link to a dedicated external page (which can have a more detailed check list?)