Get SQLite to build

* changed headers
* removed redundant declarations
* ran clang-format
* added sqlite3.mk

third_party/sqlite3/expr.c

@@ -12,7 +12,9 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 */
-#include "sqliteInt.h"
+#include "third_party/sqlite3/sqliteInt.h"
+
+/* clang-format off */
 
 /* Forward declarations */
 static void exprCodeBetween(Parse*,Expr*,int,void(*)(Parse*,Expr*,int,int),int);