Added toUnicode for special cases #20

Please see issue #20 for more information.

I created two functions (methods). toUnicode and to shortnameToUnicode which changes shortnames back into unicode. This is especially useful when using desktop notifications and if sending back to a mobile device (think sms).

In toUnicode I convert all unicode characters to shortname then back to unicode so that there is consistency between receiving device, emojione and sending device (so that the "same" unicode is presented to each)

I also updated the unit tests so that they will/would test these new functions.

I only did this in javascript but I can do it in PHP as well if requested.