Update building_spotbugs_plugin.txt
Update building_spotbugs_plugin.txt

* Windows uses double backslashes in properties files
* Since the new smart import wizard it is important to not try to import the root level project, since there would be a name clash between the root spotbugs project and the spotbugs\spotbugs project.

I managed to setup my workspace with these changed instructions.
johnscancella/spotbugs,KengoTODA/spotbugs,spotbugs/spotbugs,spotbugs/spotbugs,KengoTODA/spotbugs,sewe/spotbugs,johnscancella/spotbugs,johnscancella/spotbugs,spotbugs/spotbugs,johnscancella/spotbugs,spotbugs/spotbugs,KengoTODA/spotbugs,sewe/spotbugs,spotbugs/spotbugs,sewe/spotbugs,KengoTODA/spotbugs,sewe/spotbugs