Added multiple new open() methods to Common::File, which make it possible to use this class as a generic convenience wrapper around all kinds of SeekableReadStream; also renamed the name() method to the less confusing getName()

Files:
modified: /scummvm/trunk/common/file.cpp (try)
modified: /scummvm/trunk/common/file.h (try)
modified: /scummvm/trunk/engines/saga/music.cpp (try)
modified: /scummvm/trunk/engines/scumm/resource.cpp (try)