* signing prefix added

* Minor improvement

* Tests changed

* Successfully tested

* Minor improvements

* Minor improvements

* Revert "Dangling commas are now required. (#1359)"

This reverts commit a6889776.

* updates

* fixes #1404

* approve failing test

* suggested changes done

* ISafeERC20 removed

* allowance methods in library

* Improved SafeERC20 tests.

* Fixed test coverage.

(cherry picked from commit 315f426f)