In order to make "help" behave more consistently for decorated and undecorated commands, argparse output is temporarily redirected to self.stdout.  So doing "help history" is similar to "help load".

However, when using the "-h" with argparse commands without using the "help" command, the output from argparse isn't redirected to self.stdout.  Fixing this would be rather difficult and would essentially involve creating a pyparsing rule to detect it at the parser level.

Also:
- Reanamed foo and bar subcommand methods to base_foo and base_bar

History changes:
- Unknown commands are no longer saved in the history
- history command now has a -t option to generate a transcript based on commands in the history

Also:
- Moved examples transcripts from examples to examples/transcripts
- Added a new transcript for use with the pirate.py example

Also added a section on Sub-commands to the documentation.

Also bumped version to 0.8.0.

Updated unit tests due to changes in how help is output for commands decorated with an argparse ArgumentParser.

I eliminated a few "narg=1" configurations so that a single str value is returned instead of a List[str].

I also reworded some documentation which was no longer correct after the last commit which made "history command" have the same help text as "command -h" when using one of the two argparse decorators.

Now "help command_name" and "command_name -h" provide exactly the same text.

The function docstring for the "do_*" command sets and overrides the ArgumentParser "description" if the docstring is not empty.

Removed usage of and reference to attributes and commands which have now been removed.