Improving IOStream::print dump of memory buffer.
Refactoring Shell; improving code structure and naming of internal member functions.
Improving CosaShell.

1. New memory dump command.
2. New micros and seconds command.
3. New repeat command
4. New tone play command.
Improving CFFS shell example sketch.

1. Improved cat to allow list of files.
2. Renamed size to du.
3. Renamed ls option --verbose to -v.
4. Improved od to allow base setting.