On July 24, more than three weeks before “The Expendables 3” is due in theaters, Lionsgate learned that its ensemble actioner had been uploaded to the Internet. This was no shaky camcorded copy either, but a DVD-quality file. After a week of writing unanswered letters to the anonymous operators of the torrent sites where the film was available demanding it be taken down, the studio is suing “John Does 1-10” for unspecified monetary damages and is seeking injunctions prohibiting the sites…