Refactoring: Move options from cli.py to cli_opts.py

The cli.py module exceeded our max-module-lines limit and needs to be
split.

This pulls out all command line option definitions into a separate module.

It uses cli_opts instead of cli.opts since importing a module below
your own path causes problems if you want to re-export everything
from the lower module (which we want in this case).
Signed-off-by: Niklas Hambuechen <niklash@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Makefile.am

@@ -420,6 +420,7 @@ pkgpython_PYTHON = \
 	lib/backend.py \
 	lib/bootstrap.py \
 	lib/cli.py \
+	lib/cli_opts.py \
 	lib/compat.py \
 	lib/config.py \
 	lib/constants.py \

lib/client/gnt_os.py

@@ -265,7 +265,12 @@ def ModifyOS(opts, args):
   @return: the desired exit code
 
   """
-  os = args[0]
+  # We have to disable pylint for this assignment because of a Pylint bug:
+  # Even though there is no `os` in scope, it claims
+  #   Redefining name 'os' from outer scope
+  # It is supposed to come from `from ganeti.cli import *`, but that doesn't
+  # export `os` since it has `__all__` set.
+  os = args[0]  # pylint: disable=W0621
 
   if opts.hvparams:
     os_hvp = {os: dict(opts.hvparams)}