Remove obsolete management command

While this may have served a purpose at one point, it's now been broken
for more than 2 years [1]; a critical code path makes a call to a
function which is no longer imported.

[1] commit 84cb0ce9
    Date:   Fri Dec 21 13:15:37 2012 -0500

lms/djangoapps/courseware/management/commands/metadata_to_json.py

-"""
-A script to walk a course xml tree, generate a dictionary of all the metadata,
-and print it out as a json dict.
-"""
-import sys
-import json
-
-from collections import OrderedDict
-from path import path
-
-from django.core.management.base import BaseCommand
-
-from xmodule.modulestore.xml import XMLModuleStore
-from xmodule.x_module import policy_key
-
-
-def import_course(course_dir, verbose=True):
-    course_dir = path(course_dir)
-    data_dir = course_dir.dirname()
-    course_dirs = [course_dir.basename()]
-
-    # No default class--want to complain if it doesn't find plugins for any
-    # module.
-    modulestore = XMLModuleStore(
-        data_dir,
-        default_class=None,
-        course_dirs=course_dirs
-    )
-
-    def str_of_err(tpl):
-        (msg, exc_str) = tpl
-        return '{msg}\n{exc}'.format(msg=msg, exc=exc_str)
-
-    courses = modulestore.get_courses()
-
-    n = len(courses)
-    if n != 1:
-        sys.stderr.write('ERROR: Expect exactly 1 course.  Loaded {n}: {lst}\n'.format(
-            n=n, lst=courses))
-        return None
-
-    course = courses[0]
-    errors = modulestore.get_course_errors(course.id)
-    if len(errors) != 0:
-        sys.stderr.write('ERRORs during import: {0}\n'.format('\n'.join(map(str_of_err, errors))))
-
-    return course
-
-
-def node_metadata(node):
-    # make a copy
-    to_export = ('format', 'display_name',
-                 'graceperiod', 'showanswer', 'rerandomize',
-                 'start', 'due', 'graded', 'hide_from_toc',
-                 'ispublic', 'xqa_key')
-
-    orig = own_metadata(node)
-    d = {k: orig[k] for k in to_export if k in orig}
-    return d
-
-
-def get_metadata(course):
-    d = OrderedDict({})
-    queue = [course]
-    while len(queue) > 0:
-        node = queue.pop()
-        d[policy_key(node.location)] = node_metadata(node)
-        # want to print first children first, so put them at the end
-        # (we're popping from the end)
-        queue.extend(reversed(node.get_children()))
-    return d
-
-
-def print_metadata(course_dir, output):
-    course = import_course(course_dir)
-    if course:
-        meta = get_metadata(course)
-        result = json.dumps(meta, indent=4)
-        if output:
-            with file(output, 'w') as f:
-                f.write(result)
-        else:
-            print result
-
-
-class Command(BaseCommand):
-    help = """Imports specified course.xml and prints its
-metadata as a json dict.
-
-Usage: metadata_to_json PATH-TO-COURSE-DIR OUTPUT-PATH
-
-if OUTPUT-PATH isn't given, print to stdout.
-"""
-
-    def handle(self, *args, **options):
-        n = len(args)
-        if n < 1 or n > 2:
-            print Command.help
-            return
-
-        output_path = args[1] if n > 1 else None
-        print_metadata(args[0], output_path)