Added -o path parameter

[aonez]

Added -o path parameter to specify a custom destination/name for the output file.

• Applies -k and only applies if -c is not used.
• If the parameter points to a directory it uses the current naming method.
• If the parameter points to a new file uses it as a custom name.

Compression examples

# Will output at ./custom_name.tar.sz
snzip -o custom_name.tar.sz archive.tar

# Will output at /some/path/archive.tar.sz
snzip -o /some/path archive.tar

# Will output at /some/path/custom_name.tsz
snzip -o /some/path/custom_name.tsz archive.tar

# Will output at /some/path/no_extension_file
snzip -o /some/path/no_extension_file archive.tar

Uncompression examples

# Will output at ./custom_name.txt
snzip -d -o custom_name.txt archive.txt.sz

# Will output at /some/path/archive.txt
snzip -d -o /some/path archive.txt.sz

# Will output at /some/path/custom_name.txt
snzip -d -o /some/path/custom_name.txt archive.txt.sz

# Will output at /some/path/no_extension_file
snzip -d -o /some/path/no_extension_file archive.txt.sz