blockchain split into few separate submodules, cleanup insert_block process

ethcore/src/blockchain/block_info.rs

@@ -0,0 +1,19 @@
+use util::hash::H256;
+use util::uint::U256;
+use header::BlockNumber;
+
+pub struct BlockInfo {
+	pub hash: H256,
+	pub number: BlockNumber,
+	pub total_difficulty: U256,
+	pub location: BlockLocation
+}
+
+pub enum BlockLocation {
+	CanonChain,
+	Branch,
+	BranchBecomingCanonChain {
+		ancestor: H256,
+		route: Vec<H256>
+	}
+}