Decouple contract from balances (#2081)

* decouple contract from balance

* update impls and builds

* set fees in contract module

* builds

substrate/node/runtime/wasm/Cargo.lock

@@ -2204,7 +2204,6 @@ dependencies = [
  "sr-primitives 0.1.0",
  "sr-sandbox 0.1.0",
  "sr-std 0.1.0",
- "srml-balances 0.1.0",
  "srml-support 0.1.0",
  "srml-system 0.1.0",
  "srml-timestamp 0.1.0",