Move third-party TinyMCE out of soc/content/js and into the application image root, like other third-party code. Update the app.yaml.template to add /tiny_mce as a source of static content.

from django.conf.urls.defaults import *

urlpatterns = patterns('django.contrib.flatpages.views',
    (r'^(?P<url>.*)$', 'flatpage'),
)