LoginFilter modified to send redirect when login is done with parameters
and to return a 403 error when accesing Rest API without authorization.

Access to any resource except index.html can be restricted enabling the
LoginFilter in the web.xml configuration file. It is currently disabled.

Old index.html moved to main.html and replaced with an index.html that
contains a login form.

RESTful API modified to use PUT, DELETE, POST and GET methods.

In this first version, this applicacion includes a complete CRUD using
an AJAX+JSON+REST architecture.