working ui

click the buttons to add things
select a category or item to add an item
backspace key can delete items, whole categories, or relations
if an ordered relation is found, the first category is treated as
ordered, and the ui will not allow an ordered relation with two items of
the ordered category (you can't assign order to things that already have
an order)
click export to save the list
Merge pull request #2 from Gailbear/master

getting the files
Merge pull request #3 from Gailbear/master

getting the files
Merge pull request #4 from Gailbear/master

getting the files
Merge pull request #5 from Gailbear/master

getting the files
Merge pull request #3 from gregoryloden/master

incorporating changes