Move Image/ImageChunk/PatchChunk declaration into header files

1. Move the declaration of the Image classes to the header file to make
testing easier.
2. Also move rangeset.h to bootable/recovery to allow access in imgdiff.

Test: recovery component test
Change-Id: I68a863e60a3f2e7ae46ee48f48eb15391f5f4330
diff --git a/updater/blockimg.cpp b/updater/blockimg.cpp
index a0b9ad2..fe21dd0 100644
--- a/updater/blockimg.cpp
+++ b/updater/blockimg.cpp
@@ -53,8 +53,8 @@
 #include "error_code.h"
 #include "ota_io.h"
 #include "print_sha1.h"
+#include "rangeset.h"
 #include "updater/install.h"
-#include "updater/rangeset.h"
 #include "updater/updater.h"
 
 // Set this to 0 to interpret 'erase' transfers to mean do a