Adding basic todo app

Current version does
  * add a task description
  * on checking the box does transition to grey.
  * Unchecking does make it black again.
  * on empty text entry it does do Toast asking for input.
Basic Todo app

This app is made by following instructions.
It does create and remove todoitems from list.
Current version does not save items to file.
adding commons-io library and docs
Added functionality for saving list to text file and loading upon startup.
Merge pull request #2 from vishalpatel/ShouldDo

Sample ToDo Application in Android