Improve Xsendfile tools, allow dump whenever the conf is disabled
Remove disk IO on media_subdef::get_size
Merge pull request #986 from romainneutron/remove-disk-io

[3.8] Remove disk IO on media_subdef::get_size
Merge pull request #983 from romainneutron/xsendfilecommands

[3.8] Improve Xsendfile tools, allow dump whenever the conf is disabled
Merge branch '3.8'