Changes size of tree node square

- Tree node square size has been increased from 5 to 10.
Changes perspective of tree diagram

- Tree diagram now uses a 2D orthographic projection matrix. This
simplifies the translation of mouse clicks to tree co-ordinates.
Changes multiplier in tree draw child function

- The tree draw function now utilises the maximum number of nodes on a
specific depth as the multiplier. Probably not the best thing to do,
but it seems to preserve spacing.
- Adds max depth search in tree depth counter function.
Adds tree depth assignment on depth counting

- To quickly search for a node at a specific depth, the depth counter
now assigns a node’s depth to the TreeDepthAssignment array.