Refactor drivers definition and compilation

- Rename 'server' driver to 'mysql'
- MySQL driver is no longer the required default
- Fix compiled SQLite single-driver Adminer
- Allow to compile only selected drivers

editor/sqlite.php

@@ -2,16 +2,16 @@
 function adminer_object() {
 	include_once "../plugins/plugin.php";
 	include_once "../plugins/login-password-less.php";
-	
+
 	class AdminerCustomization extends AdminerPlugin {
 		function loginFormField($name, $heading, $value) {
-			return parent::loginFormField($name, $heading, str_replace('value="server"', 'value="sqlite"', $value));
+			return parent::loginFormField($name, $heading, str_replace('value="mysql"', 'value="sqlite"', $value));
 		}
 		function database() {
 			return "PATH_TO_YOUR_SQLITE_HERE";
 		}
 	}
-	
+
 	return new AdminerCustomization(array(
 		// TODO: inline the result of password_hash() so that the password is not visible in source codes
 		new AdminerLoginPasswordLess(password_hash("YOUR_PASSWORD_HERE", PASSWORD_DEFAULT)),