Get SQLite to build

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

third_party/sqlite3/whereexpr.c

@@ -16,8 +16,9 @@
 ** readability and editabiliity.  This file contains utility routines for
 ** analyzing Expr objects in the WHERE clause.
 */
-#include "sqliteInt.h"
-#include "whereInt.h"
+#include "third_party/sqlite3/sqliteInt.h"
+#include "third_party/sqlite3/whereInt.h"
+/* clang-format off */
 
 /* Forward declarations */
 static void exprAnalyze(SrcList*, WhereClause*, int);