add bonus data feature to imgdiff/imgpatch/applypatch

The bonus data option lets you give an additional blob of uncompressed
data to be used when constructing a patch for chunk #1 of an image.
The same blob must be available at patch time, and can be passed to
the command-line applypatch tool (this feature is not accessible from
edify scripts).

This will be used to reduce the size of recovery-from-boot patches by
storing parts of the recovery ramdisk (the UI images) on the system
partition.

Change-Id: Iac1959cdf7f5e4582f8d434e83456e483b64c02c

applypatch/applypatch.h

@@ -55,7 +55,8 @@ int applypatch(const char* source_filename,
                size_t target_size,
                int num_patches,
                char** const patch_sha1_str,
-               Value** patch_data);
+               Value** patch_data,
+               Value* bonus_data);
 int applypatch_check(const char* filename,
                      int num_patches,
                      char** const patch_sha1_str);
@@ -79,7 +80,8 @@ int ApplyBSDiffPatchMem(const unsigned char* old_data, ssize_t old_size,
 // imgpatch.c
 int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
                     const Value* patch,
-                    SinkFn sink, void* token, SHA_CTX* ctx);
+                    SinkFn sink, void* token, SHA_CTX* ctx,
+                    const Value* bonus_data);
 
 // freecache.c
 int MakeFreeSpaceOnCache(size_t bytes_needed);