Code review comment for lp:~jelmer/bzr-builddeb/lazy-1

The attached patch improves the import overhead of bzr-builddeb by:

 * lazily registering all commands (moved to cmds.py)
 * using absolute imports everywhere, and no longer updating sys.path to
   include "bzrlib.plugins.builddeb"

It seems intrusive, but mainly just moves code from __init__.py to cmds.py.

In practice, this means having bzr-builddeb enabled will only load the
__init__.py file if you're not using it.