USD Coin Sorter (Quarters, Dimes, Nickels, Pennies) for .5mm nozzle

Remixed from [this auto coin sorter](http://www.thingiverse.com/thing:499177)

I edited the OpenSCAD file to change the nozzle size from .4 to .5 and the coin arrays to just support the main four USD coins (Pennies, Nickels, Dimes, Quarters)

I tried to print KeelinJ's remix but the back of the basebox didn't print since my nozzle is a little bigger than the Ultimaker

**Instructions for use**
To store a coin, you may release a coin from the rightmost top, and it will slide down the hill