Added TYPE_BIGPK to Schema
Corrected schema used for MySQL
Fixes #875: Security::generateRandomKey() can now be safely used in URLs
Security::generateRandomKey enhancements:

- Equals sign is now replaced with dot.
- Slash is now replaced with dash.
- Better phpdoc.
Better phpdoc for AccessControl
Basic application enhancements.

- 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.
Advanced application enhancements.

- 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".
renamed Request::csrfTokenName to csrfVar.
added version, csrfVar and csrfToken to yii js module.
Modified js registration position.