fs.rename but works across devices. same as the unix utility 'mv'
var mv = require'mv';mv'source/file' 'dest/file'// done. it tried fs.rename first, and then falls back to// piping the source file to the dest file and then unlinking// the source file.;
mv'source/dir' 'dest/a/b/c/dir' mkdirp: true// done. it first created all the necessary directories, and then// tried fs.rename, then falls back to using ncp to copy the dir// to dest and then rimraf to remove the source dir;
mv'source/file' 'dest/file' clobber: false// done. If 'dest/file' exists, an error is returned// with err.code === 'EEXIST'.;