Add next/previous labels 

this is a fix for https://github.com/KidSysco/jquery-ui-month-picker/issues/6 - adds next/previous labels to translation attribute, and applies them to the markup.
Update for Open Month Picker button text Fix: https://github.com/KidSysco/jquery-ui-month-picker/issues/8

https://github.com/KidSysco/jquery-ui-month-picker/issues/8
Add text to forward/back buttons https://github.com/KidSysco/jquery-ui-month-picker/issues/6

Revised fix for https://github.com/KidSysco/jquery-ui-month-picker/issues/6
Update MonthPicker.2.1.js
Merge pull request #7 from swd120/master

Add next/previous labels