Refactoring

[fetrarij]

• change to ngModel & ngModelChange instead of date & onChange so we can work with angular form.
• I ve noticed also the bug with the linked datepicker ( issue #3 ), which is linked to the issue #28 (updating maxDate with another picker), the issue is about the immutable object (Object are not detected by change) so the solution is using doCheck and KeyValueDiffer.
• Finally, I think exposing the datepicker main class in the directive and giving the ability to export the directive is a good idea, so we could use for example ViewChild() to access all method of the datepicker & options manually , for advanced usage.

These issues will be resolved: #3 #11 #25 #28 Issues should be resolved with previous PR: #7 #8 #18 #20 #26

[fetrarij]

the result of the examples after a build -prod: https://fetrarij.github.io/ng2-eonasdan-datetimepicker/

I think we should activate gh-pages too.

[atais]

wow that is a lot. please give me couple of days.