message: Slightly improve toco error messages.
diff: @@ -1035,10 +1035,10 @@ void CheckEachArray(const Model& model) {
  if (colon_pos != string::npos) {
  CHECK_EQ(name.substr(colon_pos + 1).find_first_not_of("0123456789"),
  string::npos)
  - << "Array name must only have digits after colon";
  + << "Array '" << name << "' has non-digit characters after colon.";
  }
  - CHECK_GT(colon_pos, 0)
  - << "First character of array name must not be a colon.";
  + CHECK_GT(colon_pos, 0) << "Array '" << name
  + << "' must not start with a colon.";
  }
  }
  