Sort directories first, then by name (default sort)
Return all entries in one table, like `ls` does.  Use a formatting
function for the bytes like `ls -h`
Implementation of format function for file sizes
We need the full path to open a file and os.FileInfo.Name() only gives the base name
Pass the full path to file and directory handling functions
Much better template for the directory listing
Hover effects for directory listing.  Other aesthetics.