message: Bump version to 0.18.3
  Update copyright year
diff: @@ -2,11 +2,11 @@ dnl require autoconf 2.60 (AS_ECHO/AS_ECHO_N)
  AC_PREREQ([2.60])
  define(_CLIENT_VERSION_MAJOR, 0)
  define(_CLIENT_VERSION_MINOR, 18)
  -define(_CLIENT_VERSION_REVISION, 2)
  +define(_CLIENT_VERSION_REVISION, 3)
  define(_CLIENT_VERSION_BUILD, 0)
  define(_CLIENT_VERSION_RC, 0)
  define(_CLIENT_VERSION_IS_RELEASE, true)
  -define(_COPYRIGHT_YEAR, 2019)
  +define(_COPYRIGHT_YEAR, 2020)
  define(_COPYRIGHT_HOLDERS,[The %s Developers])
  define(_COPYRIGHT_HOLDERS_SUBSTITUTION,[[Qtum Core]])
  AC_INIT([Qtum Core],m4_join([.], _CLIENT_VERSION_MAJOR, _CLIENT_VERSION_MINOR, _CLIENT_VERSION_REVISION, m4_if(_CLIENT_VERSION_BUILD, [0], [], _CLIENT_VERSION_BUILD))m4_if(_CLIENT_VERSION_RC, [0], [], [rc]_CLIENT_VERSION_RC),[https://github.com/qtumproject/qtum/issues],[qtum],[https://qtum.org/])
  