Tilecloud-chain

1. Change the validator and parser => duplicate key generate an error: on/off are no more considered as boolean.
2. The argument --layer is no more used when we use the parameter --tiles, we get the information from the
tiles file.
3. Be able to mutualise the service.
4. Add Azure blob storage
5. Remove Apache and MapCache
6. Remove the `log_format` in the `generation` configuration, nor we use the logging configuration from the
`development.ini` file.

1. Change the config validator who is a little bit more strict.

1. Add optional `metadata` section to the config file. See the scaffolds for example.

1. Correct some error with slash.
2. Better error handling.
3. Be able to have one error file per layer.

1. Correct some error with slash.
2. Add `pre_hash_post_process` and `post_process`.
3. Add copy command.

1. Support of deferent geoms per layers, requires configuration changes, old version:

> yaml
> connection: user=www-data password=www-data dbname=<db> host=localhost
> sql: <column> AS geom FROM <table>
>
>
> to new version:
>
> yaml
> connection: user=www-data password=www-data dbname=<db> host=localhost
> geoms:
> - sql: <column> AS geom FROM <table>
>
>
> More information in the **Configure geom/sql** chapter.

2. Update from `optparse` to `argparse`, and some argument refactoring, use `--help` to see the new version.
3. Add support of Blackbery DB (`bsddb`).
4. The tile `server` is completely rewrite, now it support all cache, `REST` and `KVP` interface,
`GetFeatureInfo` request, and it can be used as a pyramid view or as a `WSGI` server. More information in
the **istribute the tiles** chapter.
5. Add three strategy to bypass the proxy/cache: Use the headers `Cache-Control: no-cache, no-store`,
`Pragma: no-cache` (default). Use localhost in the URL and the header `Host: <host_name>` (recommended).
Add a `SALT` random argument (if the above don't work). More information in the **Proxy/cache issue**
chapter.
6. Improve the dimensions usage by adding it ti the WMS requests, And add a `--dimensions` argument of
`generate_tiles` to change the dimensions values.
7. Extract generate_cost and generate_amazon from generate_controler.
8. Now we can creates legends, see the **Legends** chapter.
9. Now the tiles generation display generation statistics at the ends.
10. The EC2 configuration is moved in a separate structure, see README for more information.