CustomActor: rename "prefix" in panel to "typeName"

[hallvors]

As I've just tried to write an extension based on this example, one of the gotchas that took a while to figure out was that the value for prefix set on line 122 in myPanel.js must match the value of typeName set on line 42 in myActor.js.

If these do not match, registering the actor fails:

Handler function DebuggerClient.requester request callback threw an exception: Error: Can't manage front without an actor ID

I suggest changing to work "prefix" to "typeName" to make it at least a bit clearer that these strings are related.

[hallvors]

@janodvarko - thoughts?

[janodvarko]

(just got back from my vacation)

@hallvors: yes, this is nice improvement.

Honza