TwistyPuzzleLib

Progress with PuzzleTester app.

Correect JSON reading and writing: shape corners and centers are optional!

JsonReader (?) finished: the creator app can now read objects from JSON files.

Do not pull the inventors and the names of objects from Resources.

new API to make is possible to adjust default scale factor in each TwistyObjectNode.
(and use it in Tutorials, where the object needs to be smaller)

Major change: separate the notion of a TwistyObject and its Node. Now,

1) the Node stays when we change objects (this makes transitions faster)
2) it's possible to just create an Object without adding it to the Screen (now app needs to explicitly create the Node and add it to its Screen itself)

Standarize icon naming scheme.

Systematic names for the meshes.

Separate the notions of a sticker shape and a sticker color.

simplify sticker/color map.