Added Command Description and also command dump

[wx4cb]

No description provided.

[fakufaku]

Thanks for the pull request. I have two suggestions.

1. Changing the code from using Serial to a stream will break the existing code, so unless there are really important benefits, I would not do that.
2. Can we make the description optional by providing a NULL as description ? In which case no memory would be allocated.

[wx4cb]

1. EDIT: I misread the code. that shouldn't be an issue to change back

2. as far as using a NULL, it would still have to allocate at least 1 byte and that should already be accepted by the code as using a null in the description the description would be "\0\0"