For major release (0.10.0):
===========================

* sequencing:
   - allow generation of unique sequences based on date time for last 1 - n days, via menu
   
* download profiles (combinations of subfolder and image renaming preferences)
* better handle preference changes while downloads are occurring
* handle unexpected media removal, disk full, all kinds of write errors
* indicate different levels of error better in log window
* sum amount of images to be downloaded, and how much free space on the file system
* check download locations and sources still valid when starting the application
* rework checkPrefsForValidity() to account for multiple subfolder problems

For future releases:
====================

* Better application icon -- help needed!
* Get more metadata
  - lens
* User defined camera model mapping
* Job codes
* use python's high performance deque to improve idletube