Adding table element

Without this table element, DP does not work
Adding on change callback

Adding an onchange trigger on the on change attribute value of the
final input
Adding callback demo sample

Adding callback demo sample to explain how it works
Adding toString function

Returns a human friendly date from a yyyy-mm-dd string
code cleanup

Remove useless rewrited code
Update README

Adding onchange callback documentation
update README

remove typo
update README

Adding some API documentation
Merge pull request #4 from remi-grumeau/v1.1

V1.1