implement recursive indirect blocks

improve efficiency of multilayered indirect blocks

clean up tests

panic cleanup

clean up logic, improve readability

add final root node to the dagservice upon creation

importer: simplified dag generation

test: updated hashes using latest code

@whyrusleeping this is why the sharness tests
were failing: the hashes are added manually to
make sure our generation doesn't change.

cleanup after CR

fix merkledag tests

fix small block generation (no subblocks!)

splitting.go

@@ -9,7 +9,8 @@ import (
 
 var log = util.Logger("chunk")
 
-var DefaultSplitter = &SizeSplitter{Size: 1024 * 256}
+var DefaultBlockSize = 1024 * 256
+var DefaultSplitter = &SizeSplitter{Size: DefaultBlockSize}
 
 type BlockSplitter interface {
 	Split(r io.Reader) chan []byte