Copy a file or directory. The directory can have contents. Like `cp -r`.
Options:
- clobber (boolean): overwrite existing file or directory
- dereference (boolean): dereference symlinks
- clobber (boolean): overwrite existing file or directory, default is `true`.
- dereference (boolean): dereference symlinks, default is `false`.
- preserveTimestamps (boolean): will set last modification and access times to the ones of the original source files, default is `false`.
- filter: Function or RegExp to filter copied files. If function, return true to include, false to exclude. If RegExp, same as function, where `filter` is `filter.test`.