[ADD] oe: provides sane (unfucked) command-line interface.

The implementation is far from perfect. Some improvements are waiting in
its previous location: lp:~openerp/openerp-command.

Some docs are provided, see doc/openerp-command.rst and
doc/adding-command.rst.

bzr revid: vmt@openerp.com-20130111134657-im2f3uqjluyo4pm6

doc/adding-command.rst

@@ -0,0 +1,34 @@
+.. _adding-command:
+
+Adding a new command
+====================
+
+``oe`` uses the argparse_ library to implement commands. Each
+command lives in its own ``openerpcommand/<command>.py`` file.
+
+.. _argparse: http://docs.python.org/2.7/library/argparse.html
+
+To create a new command, probably the most simple way to get started is to
+copy/paste an existing command, say ``openerpcommand/initialize.py`` to
+``openerpcommand/foo.py``. In the newly created file, the important bits
+are the ``run(args)`` and ``add_parser(subparsers)`` functions.
+
+``add_parser``'s responsability is to create a (sub-)parser for the command,
+i.e. describe the different options and flags. The last thing it does is to set
+``run`` as the function to call when the command is invoked.
+
+.. code-block:: python
+
+  > def add_parser(subparsers):
+  >     parser = subparsers.add_parser('<command-name>',
+  >         description='...')
+  >     parser.add_argument(...)
+  >     ...
+  >     parser.set_defaults(run=run)
+
+``run(args)`` actually implements the command. It should be kept as simple as
+possible and delegate most of its work to small functions (probably placed at
+the top of the new file). In other words, its responsability is mainly to
+deal with the presence/absence/pre-processing of ``argparse``'s arguments.
+
+Finally, the module must be added to ``openerpcommand/__init__.py``.