xmlGenerator: update the README
xmlGenerator: update the README

Document the new python xml generator and deprecate the old one.

Change-Id: I5bf9a8206c82678eda7b29b1fe88cbc0396b1f9d
Signed-off-by: David Wagner <60228a510f9a76940848fa2d29321fc4edfc2119@intel.com>

anwarMov/parameter-framework,dawagner/parameter-framework,miguelgaio/parameter-framework,01org/parameter-framework,tcahuzax/parameter-framework,geekboxzone/mmallow_external_parameter-framework,AdrienMQ/parameter-framework,01org/parameter-framework,anwarMov/parameter-framework,zchokri/parameter-framework,zchokri/parameter-framework,krocard/parameter-framework,geekboxzone/mmallow_external_parameter-framework,pafonso/parameter-framework,mgaio/parameter-framework,pafonso/parameter-framework,sdnnfv/parameter-framework,AdrienMQ/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,mgaio/parameter-framework,wzairix/parameter-framework,miguelgaio/parameter-framework,wzairix/parameter-framework,01org/parameter-framework,soaresm/parameter-framework,krocard/parameter-framework,Makohoek/parameter-framework,pafonso/parameter-framework,android-ia/hardware_intel_parameter-framework,android-ia/hardware_intel_parameter-framework,sdnnfv/parameter-framework,dbrageul/parameter-framework,sdnnfv/parameter-framework,wzairix/parameter-framework,dbrageul/parameter-framework,mgaio/parameter-framework,clero/parameter-framework,zchokri/parameter-framework,soaresm/parameter-framework,AdrienMQ/parameter-framework,Makohoek/parameter-framework,android-ia/hardware_intel_parameter-framework,tcahuzax/parameter-framework,dbrageul/parameter-framework,dawagner/parameter-framework,tcahuzax/parameter-framework,anwarMov/parameter-framework,geekboxzone/mmallow_external_parameter-framework,Makohoek/parameter-framework,soaresm/parameter-framework,clero/parameter-framework,miguelgaio/parameter-framework,clero/parameter-framework