Added a check if specified path exists.
Added a check if specified path open error.
Aboid the error when specified the following path.

- On Windows
- Path is surronded by double quotation
- Last string of path is path separator
Revert "Aboid the error when specified the following path."

This reverts commit a3aad1f26ab61aa87a368869402b428e2458db80.
Avoid the error when specified the following path.

- On Windows
- Path is surronded by double quotation
- Last string of path is path separator

In this pattern(ex. pt word "dir\"), os.Args returns `dir"`.
So, unnecessary `"` must be deleted.
fixed print when with options both `--nogroup` and `-l`
Merge pull request #11 from ichizok/fix-print

Fixed print when with options both `--nogroup` and `-l`
Don't open if destination of the symlink file dosen't exist.