Reorganized system project to organize classes
Adding final comments on code and a little more reorganizing of files
Refactored too much ;-) tests failing
Fixed issue with refactoring.  Noticed a test needed for when user returns coins twice in a row.  Test fails.
Revert "Fixed issue with refactoring.  Noticed a test needed for when user returns coins twice in a row.  Test fails."

This reverts commit fd08fdbf3cc71e199b250e1c2be9e5b5d7c47aa4.
Revert "Revert "Fixed issue with refactoring.  Noticed a test needed for when user returns coins twice in a row.  Test fails.""

This reverts commit 61e28f3a2bc8d50c6b6e04a76c1536c417fd7757.
Needed to represent picking up coins based on the way I implemented vending machine.