Fixed persistency layer.

Now we have ODBC .. that accepts various connection string (including SQLite, MySQL,...)
  And EiffelStore+MySQL.
Updated sql scripts to work with MySQL, and SQLite.
Added a sql_statement (s: STRING): STRING that converts ROC sql statement to fit the underlying database engine.
 mostly to adapt incompatibilities such as AUTO_INCREMENT for MySQL and AUTOINCREMENT for SQLite
 by default SQL script should be written following MySQL SQL syntax.
Warning: to use ODBC persistence driver, it has to be installed on the target machine.

examples/demo/site/scripts/user.sql

@@ -1,34 +1,32 @@
-BEGIN;
 
-CREATE TABLE "users"(
-  "uid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK("uid">=0),
-  "name" VARCHAR(100) NOT NULL,
-  "password" VARCHAR(100) NOT NULL,
-  "salt" VARCHAR(100) NOT NULL,
-  "email" VARCHAR(250) NOT NULL,
-  "status" INTEGER,
-  "created" DATETIME NOT NULL,
-  "signed" DATETIME,
-  CONSTRAINT "name"
-    UNIQUE("name")
+CREATE TABLE `users`(
+  `uid` INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
+  `name` VARCHAR(100) NOT NULL,
+  `password` VARCHAR(100) NOT NULL,
+  `salt` VARCHAR(100) NOT NULL,
+  `email` VARCHAR(250) NOT NULL,
+  `status` INTEGER,
+  `created` DATETIME NOT NULL,
+  `signed` DATETIME,
+  CONSTRAINT `name`
+    UNIQUE(`name`)
 );
 
-CREATE TABLE "roles"(
-  "rid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK("rid">=0),
-  "name" VARCHAR(100) NOT NULL,
-  CONSTRAINT "name"
-    UNIQUE("name")
+CREATE TABLE `roles`(
+  `rid` INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
+  `name` VARCHAR(100) NOT NULL,
+  CONSTRAINT `name`
+    UNIQUE(`name`)
 );
 
-CREATE TABLE "users_roles"(
-  "uid" INTEGER NOT NULL CHECK("uid">=0),
-  "rid" INTEGER NOT NULL CHECK("rid">=0)
+CREATE TABLE `users_roles`(
+  `uid` INTEGER NOT NULL CHECK(`uid`>=0),
+  `rid` INTEGER NOT NULL CHECK(`rid`>=0)
 );
 
-CREATE TABLE "role_permissions"(
-  "rid" INTEGER NOT NULL CHECK("rid">=0),
-  "permission" VARCHAR(255) NOT NULL,
-  "module" VARCHAR(255)
+CREATE TABLE `role_permissions`(
+  `rid` INTEGER NOT NULL,
+  `permission` VARCHAR(255) NOT NULL,
+  `module` VARCHAR(255)
 );
 
-COMMIT;