writeDocumentToFile

Helper for writing a document to file. Has no effect if debugging is disabled.

The filename consists of a timestamp concatenated with the suffix. Ex.: if suffix is "_original" then {@code 1469541253_original.jpeg}

Destination directory is {@code ginivisionlib} inside your apps external files directory: {@code /sdcard/Android/data/your.app.id/files/ginivisionlib/}