Fixes accidentaly removed object-assign

Merged PR#13

Accepts invalid values for the input. onBlur is not triggered when th…

…e calendar is closed anymore.

Adds prop and a changelog file. Release candidate

Merge branch 'master' of https://github.com/arqex/react-datetime

Bump to version 0.4.3

Bump to v0.4.2

Add the render props to customize appearance

Fixed time not decreasing added buttons for controls