This "ForAppsToInclude" folder is for code and headers that are likely to be shared amongst apps, 
yet contain things that cannot be exposed through a WinRT DLL, such as base classes with protected
members.  

The contents may or may not be compiled into the AppCore DLL depending on whether or not they are 
needed by other code in AppCore DLL.  Code in this folder that does not need to be compiled in the 
AppCore DLL checks to see if BUILDING_IN_APPCORE_PROJECT is defined, and if so, does nothing.