Pullreq1

This pull request suggests changing the way to implement an IDP basing on Spring Web Flow instead of filters chain.
The main goal being leading to more readability and flexibility, notably reducing the IDP java code base.   
It inevitably leads to major changes in this specific project. 
Impacts on the configuration of other projects (excluding 'systests' projects), especially sample webapps, are very limited.
This pull request also supports authentication via a form, in addition to the 'BASIC' authentication initially provided in the base repository 'apache/cxf-fediz'
Projects 'systests' were redesigned to better test the combination (Tomcat7/Jetty8) X ('BASIC', 'FORM').
This pull request also introduces a early support for user authentication delegated to another IDP than one protecting resources accessed (separated resource IDP/requestor IDP) but this work is still running.