To be clear:
1)  <report_results_immediately>0|1</report_results_immediately>:  It is placed in the 
cc_config.xml file.  cc_config.xml goes in the BOINC folder, and applies to all projects.
2)  
app_config.xml did not replace 
app_info.xml (aka anonymous platform).  app_config.xml is a simpler way to do some of the things app_info.xml can do, and can be used as an alternative to app_info.xml.  At least one project (WCG) will not allow anonymous platform, so app_config.xml was developed as an alternative method to adjust scheduling parameters.  app_config.xml requires later versions of 7.0.xx, but I don't recall exactly which one is started with.  Both files are project-specific, and must be placed in a project folder under BOINC.  I do not believe that you can use both at the same time for a particular project, but I haven't tested that.