Create script for generating valid test data

[zeromous]

Generating a variety safe, comprehensive datasets for testing is important.

• Generate
• typical random IMG_names and filename artifacts
• Random png or jpg output. (different exif data styles)
• Random EXIF datetime data for appropriate flags based on type. Occasionally it should skip adding metadata to test that usecase.
• Should have option to clean up of existing data before run.
• warning message!