Added support for SFW format

An SFW file is not something you come across often. This is one of the old image formats one can barely find software to process. This format is proprietary of Seattle FilmWorks – corporation that started in 1970s and developed film for motion picture and still photographs. This company is no longer in the market, and this makes processing its images more complicated. The company’s practices often involved releasing media in forms that could only be developed or opened using its own products, that’s why in most cases the user is frustrated looking through the disk collection and coming across some files with an “sfw” extension that cannot be opened. The policy of ImageConverter Plus is to provide support for the widest variety of image formats. Understanding that there are very few software applications able to open SFW format, we have just included it in our list. We also encourage our users to send us other formats they have troubles opening, and we will do our best to provide their support.