Change variable names to camel case
Merge pull request #44 from nein09/dzi-status

Change variable names to camel case
Minor: use STATIC_DIR const for static middleware too.
Config: add ALLOW_NEW_CONTENT to support closing our doors.

Fixes #43.
Minor: standardize Content class on 4-space indent.
Data: remove Content `self` & `type` properties.

Just for v1 exact compatibility. We can add them back in v2.
View: don’t hardcode content DZI path.
Fetcher: properly catch & propagate download errors.
Data files: add new DATA_DIR config.

Also created this directory on the server.
Data files: exclude from git.
Data files: add stubs/examples for local data.
Data files: add script to add data-by-URL symlinks!
Data files: implement file-based data store!

And use that as the default now.
Data: implement ready, failed, progress properties!
Data: backfill `ready`, `failed`, `progress` on Zoom.it data.
Data: move image info into `dzi` container.
Data: properly separate internal from public.

And in the process, implement saving & returning full DZI info!