ASAR problem in Electron

[markkovacs76]

If node-tar is used in Electron environment where asar file support is enabled, the entry names with extension asar will not be written correctly, because Electron uses its own 'fs' library which handles asar files as a sub-directory. Hence, Electron does offer 'original-fs' library if you want to use asar file as normal file instead of a virtual sub-directory in the modified 'fs'. It would be good if node-tar supported the 'original-fs' library by demand instead of 'fs' from electron.