Sqltree

- Add ANSI SQL as a dialect
- Support escaping quotes by doubling them in string literals
- Support scientific notation with a negative exponent
- Fix formatting for quoted identifiers that contain non-alphanumeric characters
- Support the unary `NOT` operator
- Fix formatting of `LEFT JOIN` and similar queries

- Support `SELECT ... INTO` syntax
- Support `SET TRANSACTION` syntax
- Support `a MOD B` and `a DIV b` syntax
- Support `GROUP_CONCAT()` syntax

First stable release