clang-format: [proto] Understand text-format nesting without :

Before:
  option (MyProto.options) = {
    field_c : "OK" msg_field{field_d : 123}
  };

After:
  option (MyProto.options) = {
    field_c : "OK"
    msg_field{field_d : 123}
  };

(Note that the colon after "msg_field" is optional).
clang-format: Prefer breaking after return type over template param

Before:
  typename aaaaaaaaaa<aaaaaa>::aaaaaaaaaaa aaaaaaaaaa<
      aaaaaa>::aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(bool *aaaaaaaaaaaaaaaaaa,
                                                   bool *aa) {}

After:
  typename aaaaaaaaaa<aaaaaa>::aaaaaaaaaaa
  aaaaaaaaaa<aaaaaa>::aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
      bool *aaaaaaaaaaaaaaaaaa, bool *aa) {}