skip dropbox file based on size

[louisabraham]

if the file exists and has the same size as indicated by the API, we skip it

behavior is unchanged since curl uses the -C option to resume download

if the file exists and has a greater size than indicated (weird bug I couldn't track back), we delete it

This makes the script much faster (needs only one request on already synced folders instead of one per file) and more resilient.

[louisabraham]

do NOT merge yet

[louisabraham]

ok to merge now! I needed to add the skipped files to the filesList.

I alos fixed another annoying bug that made lines like

* not found, deleting
rm: can't remove '*': No such file or directory

appear in the logs

[fsantini]

Thanks!

[louisabraham]

I have never found a project more useful to my daily life than this one, so thank you!