- relation support
- completed and refactored lua script builder

- http://redis.io/commands/eval
- http://www.lua.org/

* master: (156 commits)
  added property docs to AR test classes
  moved getPDOType() back to Command to avoid dependency on Schema
  updated @property annotations of web\Request
  moved redis out of yii\db namespace
  Fixes #884.
  Supports sending CSRF token via HTTP header.
  Use .prop() instead .attr().
  use meta tags to pass CSRF token.
  Added memcached service in Travis YAML
  fixed typo
  cleanup db `use` statements
  doc fix.
  Better strtr arguments format
  Modified js registration position.
  renamed Request::csrfTokenName to csrfVar. added version, csrfVar and csrfToken to yii js module.
  Advanced application enhancements.
  Basic application enhancements.
  Better phpdoc for AccessControl
  Security::generateRandomKey enhancements:
  Fixes #875: Security::generateRandomKey() can now be safely used in URLs
  ...

Conflicts:
	.travis.yml
	framework/yii/caching/RedisCache.php
	tests/unit/framework/caching/RedisCacheTest.php

fixes #854

Added Memcached for Travis

added version, csrfVar and csrfToken to yii js module.

- Turned on CSRF validation by default.
- Added access control for login, signup and logout for frontend application.
- Added access control for login, logout and index for backend application.
- YII_ENV is now defined for all applications.
- No trace is writted to logs if debug is turned off.
- Added default error view for frontend and backend.
- In frontend application captcha will always ask for "testme" if YII_ENV is defined as "test".

- Turned on CSRF validation by default.
- Application params are now readed before config is defined to be able to use values from params when configuring.
- Added access control for login and logout.

- Equals sign is now replaced with dot.
- Slash is now replaced with dash.
- Better phpdoc.