Add Ability to Overwrite Symbolic Links
With the --overwritesymlinks option enabled, mmirror will remove and
link existing destinations. This only applies if the existing destinations
are links not regular folders.
Add Simulate Option
The --simulate option make mmirror not change the filesystem at all.
All logging happens like normal. It would be most useful to use --simulate
with -vv logging to see what would happen.
Update Readme
Add content to the readme file.