prevents empty string to be added as a list or list item

The changes in ShoppingActivity. java can be seen clearly, and a .trim() has been added at different variables.

In EditItmeDialog.java I have only made one change, added a condition 
if(!text.equalsIgnoreCase(""))
befor line no. 384 in the old file. What this does is that if a user while editting an item edits fields but makes the item name an empty string( which should not be possible), all changes are made but the itme name reamins as it was earlier.