Re-organized structure and code

1. Added SSL support to login. Secure browsing after logging in.
2. Added important security patches and mysql escape functions
3. Fixed error message display
4. Fixed home page styles, text blocks
5. Active menu item color change in all sections
6. Customized 404 page
7. Invalid student details requests display user friendly error messages
8. Added "Message" class to display errors and confirmations messages.
(removed existing session variable for message)
9. Removed all redirects except for "index" and "login".
10. Added redirect_to_ssl method