add inventory model, ui stuff (no network  yet)

we'll make this be our actual player inventory, so he can place many
things in it and such..
allow window resize for inventory
make inventory a gridview, auto layout its items
network inventory loading
leftmargin for inventory
add inventory tooltip, retrieves the item text fine etc
a bit of a start on dragging, though i need to refactor i think
add teh qt drag and drop example

currently is all you can do in the game, since it's fullscreen.
i got the concept down, able to store a source index in the draggable
item, and the drop area is able to retrieve this when a drop is triggered.
maybe this is a better path for dragging and dropping between

the two inventories, but also between themselves. both cases
need to be handled and handled well...gonna be kinda hard
to get the state changes across the board to behave well.
d&d proof of concept...should now try to refine it and add what i need
add drag indicator, some other improvements
finally figured out how to get the source drag info from positionchanged
do not show drop indicator if it's the originating slot index
oops, only do it for the same source type, too.
fix sizing of dragtile, fix bug with drag and drop idnicator getting hidden

especially after the first+ click and such
retrieve data from model, move the inventoryslot item into its own thing

the hotbar *may* need its own kind. not fond of the lack of reuse for only
1% of a code change, but whatevs
make the slot background a separate thing, so we only drag around the item

leaving no blank spot where we dragged..looks pretty awesome
add animation for drag & drop overlay, opacity
animate inventory populate as well as window resize events

looks quite lovely
fix undefined runtime error, speed up overlay anim of slot