v0.2.3

Major Port Update! Overhauled the Port UI and backend to be more informative and more attractive!

Updates:

• Added a total credits amount on each crystal element to show how much you're spending/receiving.
• Added element to show how many of each crystals are being exchanged vs how many are in the corresponding inventory.
• Added arrows buttons to decrease/increase the exchanged amount.
• Added equivalent information on the Refuel section (and prepared the Repair section to do the same). 
• You can now buy a partial amount of fuel, which takes care of the bug from the last release.
• The buy/sell sections reset the exchange amounts to 0 each time you buy or sell. This is to prevent accidental buying/selling after you have already bought or sold something. 
• Port credits and crystals are randomized within a range each time you land at the port. This is temporary until I work on the event models that will determine these amounts depending on whats happening in the region / at the specific port
• Updated the code to store the UI elements all on a single class for each UI screen, so I can use that to update the UI instead of having to add each UI element to each controller, I just add the single class!

Thoughts/Observations:

• Still working on a solution for increasing/decreasing by multiples. Currently this is an issue because the buttons only support 'On Click' instead of a 'On Mouse Down', so holding the mouse button down does not steadily increase the number. There may be a way to adjust a multiplier that is somewhere else on screen, but overall, it ends up just adding more buttons and complexity to the screen.
• I'm drifting away from a 'crystal' based naming strategy in inventory to an 'item' based naming because I want all this methods and such that I've made to be more abstract so when other items are added to the game, it wont conflict with the naming.

Bugs:

• I didn't find any while testing the Port UI, but please throw me a comment if you see something weird happening. I would deeply appreciate it!