core: Re-unify on one OSTREE_OBJECT_TYPE_FILE

Having the archived vs not distinction in the object system wasn't
useful in light of pack files.  In fact, we should probably move
towards generating a pack file per commit by default.

src/libostree/ostree.h

@@ -23,6 +23,7 @@
 #ifndef __OSTREE_H__
 
 #include <ostree-checksum-input-stream.h>
+#include <ostree-chain-input-stream.h>
 #include <ostree-core.h>
 #include <ostree-repo.h>
 #include <ostree-mutable-tree.h>