[0.2.1] FillViewer, Logo, and Non-proportional Scale

Adds a Icon/Logo and Version Text, displayed in taskbar+toolbar and top left corner of main menu respectively. Adds fillViewer to display images that scale to fill the window (instead of the window scaling to the imagte's dimensions) and renames the "regular" viewer (used for backgrounds, scales window based on image) to resizeViewer. Adds a variable to enable/disable proportional scale, which is set to true when using resizeViewer and false with fillViewer (so when images are set to fill the screen the window can be scaled in any ratio). Closes #9 and #13.