adding a little ux to the download video and transcript links
a11y adjustment to new video and transcript links styles
Add variable to set location of config files on aws

The env variable CONFIG_ROOT is used to determine the location of the
JSON configuration files. This is useful when a deployment of the
platform is used to access different environments when executing django
commands.
Segregate the mongo db config from the modulestore config
as a first step to separating db connection from modeling
and to support location mapper and contentstore using same db config as modulestore
Change the default FROM address for bulk email
Wait between clicks for new component
Guard against StaleElementException in css_click
Clarify USE_I18N settings

@jzoldak showed me that setting `USE_I18N = DEBUG` didn't actually accomplish
what I had hoped it would -- changing DEBUG didn't also change USE_I18N.
This pull request accomplishes what I was trying to accomplish, without being
quite so clever about it.
Add retry logic if element not found
Use a better metadata_cache_key

The old code created keys like "('course', 'org')", and the space
character caused a warning from Django during tests.  Also, strings are
probably better than tuples for keys.
Suppress request logging in the LTI test server.
Write to stdout to keep messages, but not pollute tests.
Remove the now-unused import.
make drag_and_drop component work with requirejs and changed static url
Unfortunately, delete tests are still failing sporadically in Jenkins.
Merge pull request #1263 from rocha/add-config-root-env-variable-to-aws-config

Add variable to set location of config files on aws
Merge pull request #1270 from edx/will/fix-multistep-component-test

Fix for failures in component.feature
Merge pull request #1268 from edx/will/fix-problem-acceptance

Guard against StaleElementException in css_click
Merge pull request #1272 from edx/ned/remove-cache-warning-from-tests

Use a better metadata_cache_key
correct placement of baseUrl variable, use it to configure requirejs