Major Description
Currently, when you start Karaf (or connect remotely to a karaf instance), you get a shell looking like:
karaf@root>
The "root" is the karaf instance name and could be changed using the karaf.name property defined in etc/system.properties file.
The "karaf" part is hard coded in Karaf and not yet linked to users defined (especially when you enable some JAAS support using a database or LDAP backend 
).
We can consider this "karaf" as a shell name, and we could consider this as linked to the branding.
Karaf branding is looking for a org/apache/karaf/branding/branding.properties file containing a welcome property.
This property is used by the Karaf branding support (at bootstrap) to display the welcome message.
I propose to extend this branding.properties file by adding another shell.name property defining the shell name.
If the property is not found or null, we fall back to "karaf" as it is currently.