Security fixes for MailWatch

- Use a random token stored in session cookie for login
- Rehash of token and unique string for each form using a form token single use
- Use the random token throughout code to prevent XSS/CSRF problems and harden from attack
- Perform input validation and thorough sanitization on url parameters and post parameters
- Change method=get to method=post in forms throughout code and use post wherever possible   
- Set cookie session security
- Files hardened:
    - auto_release.php
        - message id and release token sanitization/validation
    - checklogin.php
        - session token, session id regeneration, reject empty fields
    - detail.php
        - set memory limit early, session token, parameter sanitization/validation, CSRF token, form post
    - do_message_ops.php
        - session token, CSRF token, parameter sanitization/validation 
    - filter.inc.php
        - ValidateColumn method, parameter sanitization/validation, CSRF token, reports token handling
    - functions.php
        - session cookie security, paramater sanitization/validation, CSRF token, LDAP escape username, fix missing pear module, secure token generation, validation logic, sanitization logic
    - lists.php
        - paramater sanitization/validation, session token, CSRF token, form post
    - login.php
        - login session token
    - logout.php
        - session cookie cleanup
    - mailq.php
        - session token, parameter sanitization/validation
    - msre_edit.php
        - session token parameter sanitization/validation, CSRF token, form post
    - msre_index.php
        - session token
    - password_reset.php
        - SSL redirect, session token, paramater sanitization/validation, form post 
    - quarantine.php
        - session token, parameter sanitization/validation
    - quarantine_action.php 
        - parameter sanitization/validation, session token
    - rep_audit_log.php
        - session token, parameter sanitization/validation, CSRF token, form post
    - rep_message_listing.php
        - session token, parameter sanitization/validation
    - rep_message_ops.php
        - session token, parameter sanitization/validation
    - reports.php
        - session token, parameter sanitization/validation, CSRF token
    - style.css
        - button CSS
    - user_manager.php
        - session token, parameter sanitization/validation, form post, CSRF token
    - viewmail.php
        - session token, parameter sanitization/validation
    - viewpart.php
        - session token, parameter sanitization/validation