Certain creative inventory item types do not "stack" properly

In the creative inventory, certain items are grouped by type - i.e. the various wool colors. Several items types, however, are not categorized properly but are rather each a category containing only themselves.

Applies to the following items:

• All tools and armors
• Arrows
• Carpets
• Glass blocks
• Glass panes
• Beds
• Saplings
• Leaves
• Most food items, with the exclusion of apples