support macOS

[nift4]

1. macOS automatically creates a .DS_Store file in basically all directories on disk. Ignore it.
2. Support nwjs 0.77.0 as 0.29.0 works terribly bad in Rosetta 2 (x86_64->arm64 translation) and was basically unplayable. nwjs 0.77.0 is the first release that supports macOS arm64
3. The official macOS port does not use a /www subfolder and the game's root directory (where latest.log is placed) is the same directory the index.html and JavaScript files are in. Adjust vfs_web to account for that fact