Sqlsite

Fixed

- Correctly add charset to Content-Type header for text responses.
- Fix Content-Length header when body contains non-ASCII characters.

Added
- New `redirect` handler to redirect incoming requests to other locations.
- The `sql` template function now supports `file=` prefix, for loading SQL from a file.
- The `existsquery` column can now contain a `file=`-prefixed filename.
- The `json` handler can now use a `file=`-prefixed filename for its config.
- The `redirect` handler can now use a `file=`-prefixed filename for its config.

Changed
- The SQLite database is now opened in read-only mode (`SQLITE_OPEN_READONLY`).
- BACKWARDS INCOMPATIBLE: changed to new `<type:param>` URL parameter syntax.
- BACKWARDS INCOMPATIBLE: changed the `exists_query` column to `existsquery`.

Initial release.