[stable] Backports (#8133)

* updater: apply exponential backoff after download failure (#8059)

* updater: apply exponential backoff after download failure

* updater: reset backoff on new release

* Limit incoming connections.  (#8060)

* Limit ingress connections
* Optimized handshakes logging

* Max code size on Kovan (#8067)

* Enable code size limit on kovan

* Fix formatting.

* add some dos protection (#8084)

* more dos protection (#8104)

* Const time comparison (#8113)

* Use `subtle::slices_equal` for constant time comparison.

Also update the existing version of subtle in `ethcrypto` from
0.1 to 0.5

* Test specifically for InvalidPassword error.

* revert removing blooms (#8066)

* Revert "fix traces, removed bloomchain crate, closes #7228, closes #7167"

This reverts commit 1bf62038678295e5586f02a38a0c5aab9a9efe62.

* Revert "fixed broken logs (#7934)"

This reverts commit f8a2e53f3e.

* fixed broken logs

* bring back old lock order

* remove migration v13

* revert CURRENT_VERSION to 12 in migration.rs

* Fix compilation.

* Check one step deeper if we're on release track branches

* add missing pr

* Fix blooms?

* Fix tests compiilation.

* Fix size.

ethcore/vm/src/schedule.rs

@@ -119,8 +119,8 @@ pub struct Schedule {
 
 /// Wasm cost table
 pub struct WasmCosts {
-	/// Arena allocator cost, per byte
-	pub alloc: u32,
+	/// Default opcode cost
+	pub regular: u32,
 	/// Div operations multiplier.
 	pub div: u32,
 	/// Div operations multiplier.
@@ -135,17 +135,20 @@ pub struct WasmCosts {
 	pub initial_mem: u32,
 	/// Grow memory cost, per page (64kb)
 	pub grow_mem: u32,
+	/// Memory copy cost, per byte
+	pub memcpy: u32,
+	/// Max stack height (native WebAssembly stack limiter)
+	pub max_stack_height: u32,
 	/// Cost of wasm opcode is calculated as TABLE_ENTRY_COST * `opcodes_mul` / `opcodes_div`
 	pub opcodes_mul: u32,
 	/// Cost of wasm opcode is calculated as TABLE_ENTRY_COST * `opcodes_mul` / `opcodes_div`
 	pub opcodes_div: u32,
-
 }
 
 impl Default for WasmCosts {
 	fn default() -> Self {
 		WasmCosts {
-			alloc: 2,
+			regular: 1,
 			div: 16,
 			mul: 4,
 			mem: 2,
@@ -153,6 +156,8 @@ impl Default for WasmCosts {
 			static_address: 40,
 			initial_mem: 4096,
 			grow_mem: 8192,
+			memcpy: 1,
+			max_stack_height: 64*1024,
 			opcodes_mul: 3,
 			opcodes_div: 8,
 		}