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/core.sql

@@ -1,28 +1,23 @@
-BEGIN;
-
-
-CREATE TABLE "logs"(
-  "id" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK("id">=0),
-  "category" VARCHAR(255) NOT NULL,
-  "level" INTEGER NOT NULL CHECK("level">=1),
-  "uid" INTEGER,
-  "message" TEXT NOT NULL,
-  "info" TEXT,
-  "link" TEXT,
-  "date" DATETIME NOT NULL
+CREATE TABLE `logs`(
+  `id` INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
+  `category` VARCHAR(255) NOT NULL,
+  `level` INTEGER NOT NULL,
+  `uid` INTEGER,
+  `message` TEXT NOT NULL,
+  `info` TEXT,
+  `link` TEXT,
+  `date` DATETIME NOT NULL
 );
 
-CREATE TABLE "custom_values"(
-  "type" VARCHAR(255) NOT NULL,
-  "name" VARCHAR(255) NOT NULL,
-  "value" TEXT
+CREATE TABLE `custom_values`(
+  `type` VARCHAR(255) NOT NULL,
+  `name` VARCHAR(255) NOT NULL,
+  `value` TEXT
 );
 
-CREATE TABLE "path_aliases"(
-  "pid" INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL CHECK("pid">=0),
-  "source" VARCHAR(255) NOT NULL,
-  "alias" VARCHAR(255) NOT NULL,
-  "lang" VARCHAR(12)
+CREATE TABLE `path_aliases`(
+  `pid` INTEGER PRIMARY KEY AUTO_INCREMENT NOT NULL,
+  `source` VARCHAR(255) NOT NULL,
+  `alias` VARCHAR(255) NOT NULL,
+  `lang` VARCHAR(12)
 );
-
-COMMIT;