Add comments about questionable URI encoding/decoding in client.
Client: submit 'ordered' parameter to prevent sorting of directories.
Report HTTP status code 500 for ImageMagick thumbnail errors.
CLI: Improved configuration.

- Supports alternate browsers and URIs
- Uses config file at ~/.config/Sequential-3/config.json
- Uses data dir at ~/.config/Sequential-3/ by default on Linux
CLI: Use HEAD instead of GET to determine whether server is running.
node-shared: Remove ugly "bt" module.
Refactoring build system a bit.

Recursive make considered confusing.
CLI: Fix path encoding problems.
CLI: Smallest refactoring, use has() instead of hasOwnProperty().