* signing prefix added * Minor improvement * Tests changed * Successfully tested * Minor improvements * Minor improvements * Revert "Dangling commas are now required. (#1359)" This reverts commita6889776f4. * updates * fixes #1404 * approve failing test * suggested changes done * ISafeERC20 removed * allowance methods in library * Improved SafeERC20 tests. * Fixed test coverage. (cherry picked from commit315f426f5c)