Create less ClassLoader instances if the client code provides different classpaths.
ModelClassPathDef no longer allows clients to specify implicitly added classpath entries.
Added static method for ModelClassPathDef to check if a classpath is implicitly assumed or not.
Fixed test codes of netbeans-gradle-default-models after enforcing that a client code may not specify implicitly specified classpath entries.
Introducing TemporaryFileManager.
GenericModelFetcher now relies on TemporaryFileManager instead of StringAsFileRef.
Removed StringAsFileRef as it is now completely replaced by TemporaryFileManager.