OO-3297: refactor the user management to use organization for managing the roles instead of named security groups

OO-2515: save the master file untouched, deliver  more pixels for the print view of the members course element, add REST api methods to check if a particular size of portrait is available

OO-1593: revert the custom identity mapping, too much side effect, it would need a refactoring of the IdentityImpl mapping

OO-1436: fix an issue with a method's signature, log audit creation of identity and authentication, show errors after import of users...

OO-1341; make the extension of the image mandatory, needed by the java scaling service to discover the type of the image

no-jira: fix a unit test which fail randomly because Grizzly change its HtppSession during processing the request

no-jira: fix documentation of REST API, fix wrong path of the LogWebService, backport RegistrationWebService to OpenOLAT with its unit tests

OO-204: refactor the DisplayPortraitManager to allow portrait saved in PNG and using the new ImageHelper implementation

OO-203: refactor the ImageHelper to use different implementation, add an implementation based on ImageMagick/GhostScript for pictures and PDFs thumbnailing

FXOLAT-296	: enhanced REST API for users, add flag to send the portrait as attribute with Base64 encoding

--HG--
branch : bps