Implement some of the flags that represent output modes

[fomgleb]

• -l - Long output
• -C - Force multi-column output; this is the default when output is to a terminal;
• -1 - (The numeric digit ``one''.) Force output to be one entry per line. This is the default when output is not to a terminal;
• -m - Stream output format; list files across the page, separated by commas.
• -x - The same as -C, except that the multi-column output is produced with entries sorted across, rather than down, the columns.