adding file creation and modified date support + more debugging output

[mfyz]

1. created files were having "now()" to their creation and modified timestamps. used flickr photo meta data to update after file creation on the fs.

2. added photo number, total photos in that page and page indicators aside of the album/photoset currently downloading for better understanding to the progress of the download. Example:

[file -  90/500 at the page 1/2 - photo set: Auto Upload] 2,647,529   2.01MB/s

[TheFox]

Cool, thank you for your Pull Request.

Please change the variables to Camel Case. For example, $total_photos has to be $totalPhotos.

For a complete list of all failed checks see: https://travis-ci.org/TheFox/flickr-cli/jobs/451572044

[mfyz]

@TheFox clean build. Let me know if need more tweaks.