Increase max_length of various char fields
Fix #5
Add avocado init option `--prepend-model-name`

The default behavior is now to *not* prepend the model name
since in practice most non-operational field names are unique.
Pass this new flag to use the previous behavior.

Fix cbmi/harvest#7
Unicode all the way down™

Fix cbmi/harvest#6
Map field => concept directly in single concept create admin action

Fix cbmi/harvest#8