CopyDirToDir Copy files from 1 directory into another.

CopyToDir Copy a file to a directory.

DirExist Those rare times when you just need to check if a string path is a directory and not a file.

Exist true for a directory/file and false otherwise.

NewReadCloser Return an io.ReadCloser from a string or content from a file.

Normalize Switch the path separator to same as the os.PathSeparator.