[stable] Postpone Kovan hard fork (#8137) (#8152)

* Postpone Kovan hard fork (#8137)

* ethcore: postpone Kovan hard fork

* util: update version fork metadata

* WASM libraries bump (#7970)

* update wasmi, parity-wasm, wasm-utils to latest version

* Update to new wasmi & error handling

* also utilize new stack limiter

* fix typo

* replace dependency url

* Cargo.lock update

util/version/Cargo.toml

@@ -13,13 +13,13 @@ build = "build.rs"
 track = "stable"
 
 # Indicates a critical release in this track (i.e. consensus issue)
-critical = false
+critical = true
 
 # Latest supported fork blocks for various networks. Used ONLY by auto-updater.
 [package.metadata.forks]
 foundation = 4370000
 ropsten = 10
-kovan = 5067000
+kovan = 6600000
 
 [dependencies]
 ethcore-bytes = { path = "../bytes" }