Added a "quick purge" option before the actual unload to insure the filament is free to pull back.
Made adjustments for "Machine Disallowed Areas".
Added some comments.
Re-ordered some of the code.
This script has 4 options.
Add Purge Lines will draw lines left, right, top, or bottom of the build plate and either fill length of half length. If a print takes up the entire width then the purge lines could be moved to the bottom.
