Changed several things to do with StructureTemplates:
Add support for structure block keys with a list of items (Fixes #7)
Add iterator to structure template
Add getters for structure template fields (I personally had a usecase where I wanted to access some of the fields)
Support pickblocking the block in the structure preview. (if a structure preview is active and you middle-click on a block, it will place it into your inventory if in creative, or take it from the items you have in your inventory if in survival)
Persist structure previews across world reloads (exiting then re-opening world)
Changed several things to do with
StructureTemplates: