compatability with iTweak Upload module

One more issue worth addressing in bulk:
3). hook_file_download() may be used to only check for file access permissions. Download count increments the counter incorrectly for such calls.

Updated patch covering all 3 issues is included.

I guess you meant fix 3) in #1...
Anyway, more explanations:

2) is straightforward - _download_count_stats() split does not change existing functionality. It just makes the download counter available to other modules in more universal way. It may be better with a new hook, but that may require some core improvements. See issue #588106: Duplicate listing of files when also using download_count.module.

3) is very specific to what itweak_upload is trying to do, but also applicable to other scenarios. ITU needs the info about the file without downloading it (checks file type). There is no API call to do it in drupal, only hook_file_download() which returns the needed information. The problem is that hook_file_download() assumes the file will be downloaded. My patch adds a second optional argument that tells it is just an info check. Otherwise download_count increments every time the page with the file is served and itweak_upload is used.

Hope that clarifies the purpose.

I'd like to know if the remaining 2 fixes can be committed to 1.x-dev and also rolled over to 2.x-dev. Module interoperability is at stake.