Fixes #5, Fixes #3

GetPO:
* Parts are now stored as text

CreateOrder:
* SIMs are now stored as text
* UOM is now pulled from master
* Price formula now results in "not on master" if an item could not be
found
* A note is entered for each line item that will be removed
* Items with errors will now be removed (Fixes #5)
* UOM is now obtained after SIMs (Fixes #3)

CreateReport:
* Added sub to format removed items

Program:
* Clean method will now be run when an error occurs