Would be nice to be able to specify (sub-)folders to be excluded by task

[csnyulas]

Some folders, for example the DCIM on the SD card of a Cannon camera, besides the sub-folders containing the images it also contains a sub-folder called CANNONMSC with a lot of .CTG files. Those should be ignored by the copy tasks.

Maybe this could be also solved if the algorithm that uses the capture date from the picture (EXIF), would ignore such .CTG files, because they are not images. However, a more general (and safer) solution would be to allow exclusions of sub-folders.