Add subcommand documentation

This adds subcommand documentation to both the common help output and to
the individual commands help.

Change-Id: I7ac84a27e90962610548b918b47da12dea896310
Added some extra environment configuration.

Change-Id: I158a534239aab7fc33a471da7db38f8eaa79feb1
Flatten task namespaces

Avoids weirdness when a task module is imported from another
module.

E.g., if the apple module imports the banana module, you would
previously end up with a task name 'apple.banana.task'. Now this
loads as 'banana.task' as expected.

Change-Id: Ie89586851784585bf30e68aba021c61565162340
Support config file format for hivemindrc

Change-Id: Ia44fbf8ebb00894e1e96b90caf9d0dcdfe1484a0
Override command defaults via config file

Change-Id: I598fde213f48d21b082953302658b729a4f08021
Add hokey config file namespace filtering

Change-Id: I5f775c1b889cc87c963008c1df8817ca30c10f41
Fix backwards compat for config

Change-Id: I8d3cc52b9746e177ba9974a207ea04c6aa8f2310
Merge "Add subcommand documentation"
Merge changes I8d3cc52b,I5f775c1b,I598fde21,Ia44fbf8e,Ie8958685,I158a5342

* changes:
  Fix backwards compat for config
  Add hokey config file namespace filtering
  Override command defaults via config file
  Support config file format for hivemindrc
  Flatten task namespaces
  Added some extra environment configuration.