On windows having a preceding "/" will cause problems, if the
command line already has C:/<export-folder/ in it. Final resulting
path on windows might become C:/C:/ this will cause problems
of starting minio server properly in distributed mode on windows.
As a special case make sure to trim off the separator.
NOTE: It is also perfectly fine for windows users to have a path
without C:/ since at that point we treat it as relative path
and obtain the full filesystem path as well. Providing C:/
style is necessary to provide paths other than C:/,
such as F:/, D:/ etc.
Another additional benefit here is that this style also
supports providing UNC paths as well.
Fixes#5136
It is possible at times due to a typo when distributed mode was intended
a user might end up starting standalone erasure mode causing confusion.
Add code to check this based on some standard heuristic guess work and
report an error to the user.
Fixes#4686
Harshavardhana