Fixes #3404: Parses CSV of redirects and creates Drupal redirects

#### What's this PR do?

Parses a script CSV of legacy and beta redirects, specifically in the format created by #3414, and saves those redirects to the Drupal `redirect` table.

More detail available in the block comments of the script itself.

#### Where should the reviewer start?

Take a look at the [redirect CSV](https://docs.google.com/a/dosomething.org/spreadsheet/ccc?key=0ApfENCbpVZv9dGNhQ2VMNnU5Ynh5Y3cwVlJhSTdHVUE&usp=sharing) and the original issue (#3404).

#### How should this be manually tested?

You can run against the "processed" tab of the [redirect CSV](https://docs.google.com/a/dosomething.org/spreadsheet/ccc?key=0ApfENCbpVZv9dGNhQ2VMNnU5Ynh5Y3cwVlJhSTdHVUE&usp=sharing).

From the Drupal root, you should be able to run

`drush --script-path=../scripts/ php-script 3404-create-redirects.php`

and check the output in the `redirect` table.

#### Any background context you want to provide?

Nein

#### What are the relevant tickets?

#3404