Enhancement and stability

This release moved the logic and input to a separate thread from the GUI.
Copying files was made more stable.
Quick navigation was added by using the left and right buttons on the main explorer UI
Seconds was added to the clock.
Images can now be zoomed, rotated, and moved around the screen.
You can now exit a text file without saving by pressing minus (this is only temporary until I make a better solution).
A message was added while deleting files so that you know the app isn't just frozen if it takes longer than expected.
Plus can now be used to exit the app from the main explorer UI more quickly (requested by muxi).
Bugs were fixed and the app is more stable in general now.
Probably other stuff I'm forgetting.

Thanks to @muxi1 and qpwoei for helping to test this release.