Planes Drag and Drop bug

The bug should be fixed now. 

Note: 
Checkout the planes directory. This is the proper way of importing modules located in your directory. It's better not to make edits to the PYTHONPATH. It can sometimes screw up python modules. The planes directory contains an __init__.py which is how you normally allow importing modules. 

Also, it is better to keep your source code and your images (or other content) separate. The images are now in images/ and their references are all changed as well. 

If you have test code, throwing that in a test/ is nice too. 

This simply improves project file management. 

If you any questions, feel free to ask away.