Fix sys.path manipulation in pavement.py, with detailed comment

Restore reverted changes from paver part 1

cms/djangoapps/contentstore/management/commands/delete_course.py

@@ -6,9 +6,6 @@ from .prompt import query_yes_no
 from contentstore.utils import delete_course_and_groups
 
 
-#
-# To run from command line: rake cms:delete_course LOC=edX/111/Foo1
-#
 class Command(BaseCommand):
     help = '''Delete a MongoDB backed course'''
 

cms/djangoapps/contentstore/management/commands/edit_course_tabs.py

@@ -5,8 +5,6 @@
 #
 # Run it this way:
 #   ./manage.py cms --settings dev edit_course_tabs --course Stanford/CS99/2013_spring
-# Or via rake:
-#   rake django-admin[edit_course_tabs,cms,dev,"--course Stanford/CS99/2013_spring --delete 4"]
 #
 from optparse import make_option
 from django.core.management.base import BaseCommand, CommandError

cms/djangoapps/contentstore/management/commands/xlint.py

@@ -1,6 +1,5 @@
 """
 Verify the structure of courseware as to it's suitability for import
-To run test: rake cms:xlint DATA_DIR=../data [COURSE_DIR=content-edx-101 (optional parameter)]
 """
 from django.core.management.base import BaseCommand, CommandError
 from xmodule.modulestore.xml_importer import perform_xlint

cms/envs/bok_choy.py

@@ -21,7 +21,7 @@ from xmodule.x_module import prefer_xmodules
 
 ######################### Testing overrides ####################################
 
-# Needed for the `reset_db` management command
+# Needed for the reset database management command
 INSTALLED_APPS += ('django_extensions',)
 
 # Redirect to the test_root folder within the repo