Enable dialect specific behaviours in the parser (#254)

* Change `Parser { ... }` to store the dialect used:
    `Parser<'a> { ... dialect: &'a dyn Dialect }`

    Thanks to @c7hm4r for the initial version of this submitted as
    part of https://github.com/ballista-compute/sqlparser-rs/pull/170

* Introduce `dialect_of!(parser is SQLiteDialect |  GenericDialect)` helper
    to branch on the dialect's type

* Use the new functionality to make `AUTO_INCREMENT` and `AUTOINCREMENT`
  parsing dialect-dependent.


Co-authored-by: Christoph Müller <pmzqxfmn@runbox.com>
Co-authored-by: Nickolay Ponomarev <asqueella@gmail.com>

src/lib.rs

@@ -35,6 +35,7 @@
 #![warn(clippy::all)]
 
 pub mod ast;
+#[macro_use]
 pub mod dialect;
 pub mod parser;
 pub mod tokenizer;