Demo update #1

Fixed a bug in the Codex where it wouldn't update/display anything.

Fixed another bug in the Codex where entries would be duplicated.

Building conveyor belts while panning the map (using WASD) should now work much better. But, as this is a highly important part of the game, please do let me know if I introduced any new bugs.

Setting window mode in options will now have immediate effect and not require a relaunch of the game.

Items with a sell value of 0 had their sell value hidden in the Codex; sell values will now always be displayed.

Made some tweaks to make up for a misunderstanding: Replacing, building on top of or removing a block will always reimburse the build cost of said block (this is not new). However, that reimbursement isn't noticeable unless you keep an eye on the balance while doing it. To eliminate any confusion, I've removed the negative floaty number that appears when replacing or building on top of another block.

To make the early game more manageable, the starting balance has been increased from 3000 to 5000.

Income and expenses associated with removing and building blocks, respectively, are now excluded from the income/expense report. That should make actual operational cost/income more transparent. Do let me know if you prefer this to be a toggle on/off in options.

Tweaked the tutorial text about the Hub a bit to make it clear that not all items have a sell value.