updated plugin to traverse child nodes

Few updates have been made to the plugin:
- Updated it to traverse any child nodes that may exist (updated read me and example files accordingly)
- Updated the plugin to use the <bdo> tag over the <span>
- Updated the dir attribute to be "auto" except for IE, that is set to "rtl"
- Added a check for numbers and punctuation to be included in the surounding <bdo>
- Separated out the different functions used into a separate object
- Some work on improving the tag clean up to better handle ajcent <bdo>'s, still needs some work