WIP
Implemented Show
Optimize concat with nil nodes
Implemented split
Renamed branch to concat
Renamed char_len to len
Split nil doesn't have to fail
Rename nodes
Implement container for node
Implement mutable for node
Optimize split
Added swap method
Added delete
Added print_debug function
Optimize append & prepend
Added insert method
Delete returns the deleted section
Removed broken char_at.
Optimize split
Use swap