connected remove command to UI
Merge branch 'master' of github.com:LucidComplex/inventory-system
added factory methods, implemented add item (still lacking category and supplier)
Merge branch 'master' of github.com:LucidComplex/inventory-system

Conflicts:
	src/commands/AddCategoryCommand.java
	src/commands/EditCategoryCommand.java
	src/commands/RemoveItemCommand.java
	src/ui/EditWindow.java