hiding features

1. added few options to hide or disable some features:
*) hiding link "wayf" on SP detail and stop generating json with list of trusted Idps by SP
   $config['featdisable']['discojuice'] = true;
*)  hiding link "wayf" on SP detail 
   $config['feathide']['discojuice'] = true;
*)    hiding links with metadata on provider detail page 
   $config['feathide']['metasonprov'] = true;

2. added subtab in provider detail to show metadat xml for entity

3. some code cleaning