Update TriangleGenomeGUI.java

-Added all the required elements to the GUI
-imageSelect is now dynamically populated from the images/ directory as opposed to being hardcoded
-fitness is now displayed on the GUI
-next and reset buttons now display a new Genome

BUGS
- when a new Genome is displayed, some buttons disappear, but reappear when the window is resized or you click where the button should be
- when a new target image is selected, ALL buttons disappear, but reappear when the window is resized or you click where the button should be
- fitness can only seem to be calculated for MonaLisa.png. A ArrayIndexOutOfBoundsException is thrown. I believe this could have something to do with only working with images with the same dimensions as MonaLisa.png, although I have not been able to test that theory out