Fix Get a list of all valid commands when writing --help

[Rohan-Salwan]

• fixed: Get a list of all valid commands when writing --help #225

[dbieber]

Note to self: This makes the change discussed at #225 (comment)

[bwtaylor]

The comments on line 326-327 should be modified to say that we do want methods and properties of classes to be accessible so that --help can show them.

[bwtaylor]

This will show class attributes that start with an _ , an inconsistency with how it works for objects. This can be easily fixed via:
return not name.startswith('_')