after tbia project.

common/helper/File.php
    * add a method that prints downloading header

common/helper/Image.php
    * safty createImageObject()
    * fixe issue of the resizing ratio
    * allow to specify a key index on uploadImage() method.
    * automatically fix image orientation after upload
    * add a method for detecting image submition.

common/models/Attachment.php
    * add column prefix support.
    * add new interface IAttachemntsRead

common/models/Configuration.php
    * add i18n support

common/views/error.html
    * add bootstrap3 support
    * add back link

config/config.php.example
    * add `enable_i18n` option
    * add `session_name` option
    * flatten google analytics options
    * add google search option

sys/core.php
    BaseController
        * add `_setJSONHeader()`
        * add `_handlePost()`

    Module
        * add `_defaultAction` property
        * add `doAction()`

    Model
        * add `_autoLastInsertId` property
        * add `setForceInsert()`

    View
        * auto load `views/functions.php` before loading layout_functions.php
        * fix bugs of addon displaying

    Search
        * add `where()`
        * add `having()`
        * add `sqlPagerInfo()`

    DBHelper
        * add `modelConfig()`

    Validator
        * add `isUniq()`
        * add `nullOrIsUniq()`
        * add `captcha()`
        * change method name `NullOrHasRecord()` to `nullOrHasRecord()`

sys/functions.php
    * add `get_file_path()`
    * add `bs3_html_checkboxes`
    * remove `breadcrumbs()` due to it was moved down to `view/functions.php`
    * add languageList()
    * add youtube()
    * add youtubeImage()