KartmakerGUI 1.0.3

~ Fixed an IDisposable not being disposed of, previously potentially leading to a memory leak. This was extremely unlikely to be a serious problem for any user as first of all the virtual machine that all C# code runs in has good enough GC that eventually the IDisposable memory would die and second of all the leak in question would take hours of one using the program, constantly doing one thing in particular over and over, to affect even a low-end machine.

~ The 'flip' optional boolean parameter for each frame defined in a Kartmaker template was previously misinterpreted during the WAD generation process to have contradictory behaviour to the original Kartmaker software. This has now been resolved. Special thanks for Discord user Spazcakes for bringing this major issue to my attention!
+ Added the 'simpleflip' optional boolean parameter for each frame defined in a Kartmaker template. This boolean (which cannot be set to true at the same time as the 'flip' optional boolean) will flip a frame the way a frame used to be flipped in versions before this release of KartmakerGUI. This 'broken' behaviour has been kept as an option because the true behaviour of the 'flip' optional bool parameter requires the end user to reconfigure how they write their layer coordinates for any frame with the 'flip' boolean set to true whereas 'simpleflip' does not require such consideration.

- Removed the warning boxes that appear when one clicks an elipses button to open a file explorer dialog but then chooses to cancel out of that dialog, seems like overkill to me.