serde is no longer util dependency (#1534)

* removed old json-tests

* simplify folds in triehash.rs

* removed unused json_aid

* removed unused squeeze.rs

* json branching tests for trie

* removing todos from util

* separated UsingQueue and Table

* further cleanup, removing unused code

* serde serialization of hash moved to rpc module

* uint wrapper for rpc in progress

* serialization of uint moved to rpc module

* updated eth-secp256k1

* updated igd, serde is no longer dependency of util

* loading trie consensus tests

* renamed aliases in rpc imports