Issue #67 - Add invoices view placeholder
Issue #67 - Restrict invoices view to logged in only
Issue #67 - create initial Invoice API structure
First minimally working Invoice classes
Issue #67 - Finish main invoice list layout
Stop using view magic methods
Refinements to Invoice classes
Minor code reformat
Issue #67 - Add invoice PDF view
Add fix menu method to install script
Don't try to use unavailable classes
Add methods for creating/deleting menus
Coupon description improvements
Invoices layout improvements
Comments about CSS classes
Minor formatting/aesthetic changes
Create v0.3.2