* Removed ability to use JSON as frontmatter. Still allowed in data/ folder.
* Added YAML data postscript. Like frontmatter, but reversed. Attach content after the key/value data as a `:postscript` key to the data structure (if Hash).
* Removed the `proxy` and `ignore` options for the `page` command in `config.rb`. Use the `proxy` and `ignore` commands instead of passing these options to `page`.
* The `page` command in `config.rb` can now be used to add data to the page via the `data` argument. It is accessed the same way as frontmatter data, via `current_resource.data`.
* Add support for `environments` with the `-e` CLI flag. Loads additional config from `environments/envname.rb`. Removed `development?` helper in favor of `environment?(:development)`. Added `server?` helper to differentiate between build and server mode.
* The preview server can now serve over HTTPS using the `--https` flag. It will use an automatic self-signed cert which can be overridden using `--ssl_certificate` and `--ssl_private_key`. These settings can also be set in `config.rb`