[exif2timestream] implement cam numbers
[run_from_cmdline] show resulting files
[exif2timestream] fix generation of csv
[exif2timestream] fix handling of mixed case

Now, subdirs and extensions can be any case. This means we can use this
on linux, as it ACTUALLY FUCKING KNOWS THE DIFFERENCE BETWEEN TWO
NUMBERS. THE FUCK, Windows.
[test/unburnable] add _dir in camupload

The timestreamiser should never look in subdirs of the source dir
starting with _. This add a valid image under a subdir starting w/ _, to
attempt to confuse find_image_files.
[run_tests] exclude exifread logging from capture
[find_image_files] misc fixes to subfolder handling
Merge pull request #19 from kdmurray91/dev

CAM_NUM implementation