Added support for toRelativeString()
Added a method to the prototype called toRelativeString() per issue #10 (and #12)
Let me know if there's anything related to this that should or could be included. I thought about adding a second parameter to set the precision or something which might be useful if someone always wanted the date in years but also wanted a tenths fraction included.
Another use case I could see would be "X years Y months ago". Perhaps the first argument could be set up to take in a prints type formatted string and the function could detect the units by inspecting the closest proceeding word? Does anyone have any feelings about this ( @powmedia ) ?
why aren't you doing the i18n stuff for this? thats one of the powers of this library.