message: singleton for inflation voting outcome
diff: #include <eosiolib/serialize.hpp>
  #include <eosiolib/multi_index.hpp>
  #include <eosiolib/privileged.hpp>
  +#include <eosiolib/singleton.hpp>
  #include <eosiolib/transaction.hpp>
  #include <array>
  @@ -22,6 +23,7 @@ namespace eosiosystem {
  using eosio::member;
  using eosio::bytes;
  using eosio::print;
  + using eosio::singleton;
  using eosio::transaction;
  template<account_name SystemAccount>
  @@ -61,6 +63,8 @@ namespace eosiosystem {
  indexed_by<N(prototalvote), const_mem_fun<producer_info, uint128_t, &producer_info::by_votes> >
  > producer_info_index_type;
  + typedef singleton<SystemAccount, N(inflation), SystemAccount, uint32_t> inflation_singleton;
  +
  struct account_votes {
  account_name owner = 0;
  account_name proxy = 0;
  @@ -163,9 +167,6 @@ namespace eosiosystem {
  acv = &avotes.emplace( voter, [&]( account_votes& a ) {
  a.owner = voter;
  a.last_update = now();
  - a.proxy = 0;
  - a.is_proxy = 0;
  - a.proxied_votes = 0;
  a.staked = amount;
  });
  } else {
  @@ -272,6 +273,8 @@ namespace eosiosystem {
  };
  set_blockchain_parameters(&concensus);
  +
  + inflation_singleton::set( inflation_rate[median] );
  }
  static void on( const stake_vote& sv ) {
  