Ability to use EXIF DateTimeOriginal instead of current time

[andreyvin]

Almost every photoframe has ability to show date time image was taken.

Thanks for the source I was able to modify code to take date from exif data, remove time, put it into right corner and set font the same as time font in up-right corner. It seems to be nice to have ability to put DateTimeOriginal from exif into Monitors->Clock with ability of format modification.