#481 Add support for last login to DatabaseServerLoginModule

[VidarVevik]

Make it possible to add:
<module-option name="loginUpdate"><![CDATA[update
principal set lastLogin=? where name=?]]></module-option>
to: login-config.xml

When a user login, database will be updatet to record
last login date.

[VidarVevik]

security/src/main/org/jboss/security/auth/spi/DatabaseServerLoginModule