Upgraded to 1.8-rc-1
GradleModelLoader chooses the new API for 1.8-rc-1 and above.
Fixed imports.
Added BuildOperationArgs.setupLongRunningOP
Fixed a null check in BuildOperationArgs.
Removed unused method from JavaSourceModelBuilder.
Added JarOutputsModelBuilder.
LongRunningOperationSetup has been replaced with OperationInitializer.
Added FetchedBuildModels.
No longer storing a reference to GradleProject. Instead, we now have GradleMultiProjectDef.
Moved StringAsFileRefTest to "netbeans-gradle-default-models".
Moved GradleMultiProjectDef and related classes to "netbeans-gradle-default-models".