Recording Tools subspec doesn't compile with frameworks due to ARC issues in KSObjCApple.h

[SSheldon]

After #127, I'm able to use KSCrash as a framework, but using the Recording Tools subspec doesn't work due to these issues:

While building module 'KSCrash':
In file included from <module-includes>:1:
In file included from KSCrash/KSCrash.framework/Headers/KSCrash-umbrella.h:26:
KSCrash/KSCrash.framework/Headers/KSObjCApple.h:488:5: warning: '__strong' only applies to Objective-C object or block pointer types; type here is 'void *' [-Wignored-attributes]
    __strong void *_store;           /* can be NULL when MutableDeque */
    ^
KSCrash/KSCrash.framework/Headers/KSObjCApple.h:581:8: error: ARC forbids Objective-C objects in union
    id strong;
       ^
1 warning and 1 error generated.
fatal error: could not build module 'KSCrash'
#import <KSCrash/KSCrash.h>
 ~~~~~~~^

Not sure how to fix this, maybe people just should use the Tools subspec with frameworks 😄

Or maybe it could be fixed by marking that this header shouldn't use ARC?

[kstenerud]

Should be fixed by 0dad7f1