Refs #360. Revert an early change so that lists cannot be converted to other containers because it breaks things in the current code.
Refs #360. Revert an early change so that lists cannot be converted to other containers because it breaks things in the current code.

samuelcole/wymeditor,samuelcole/wymeditor,samuelcole/wymeditor,samuelcole/wymeditor,samuelcole/wymeditor,samuelcole/wymeditor