Members of named imports used as anonymous fields cause syntax errors

[csams]

import time "time"

type MyDuration struct {
    *time.Duration
}

This will cause a syntax error in the relationship where "time.Duration" starts with an extraneous double quote:

@startuml
namespace namedimports {
    class MyDuration << (S,Aquamarine) >> {
    }
}
""time.Duration" *-- "namedimports.MyDuration"

@enduml

Other places where members of time are used also contain the double quote prefix, but they don't always result in syntax errors.

This bug is related to fixes for #84.