OBMFULL-3445 When the SSO is on another domain, AJAX requests detect the loss of session.
OBMFULL-5777 modernize ErrorMailerTest

Conflicts:
	java/sync/services/src/test/java/org/obm/sync/server/mailer/ErrorMailerTest.java
OBMFULL-5777 modernize EventChangeMailerTest

Conflicts:
	java/sync/services/src/test/java/org/obm/sync/server/mailer/EventChangeMailerTest.java
OBMFULL-5777 never use javax.mail.Session.getDefaultSession

	This method despite it takes arguments construct a Singleton shared
	by the whole JVM and doesn't take arguments into account after
	the first call.

	We need to create a new instance of Session everytime we need one.

Conflicts:
	java/sync/integration-testing/src/test/java/org/obm/opush/IntegrationTestUtils.java
	java/sync/opush/mail-backend-testsuite/src/main/java/org/obm/push/mail/JavaxMailTest.java
	java/sync/services/src/main/java/fr/aliacom/obm/common/MailService.java
	java/sync/services/src/main/java/fr/aliacom/obm/common/calendar/MailService.java
	java/sync/services/src/main/java/org/obm/sync/ObmSmtpProvider.java
	java/sync/services/src/main/java/org/obm/sync/server/mailer/AbstractMailer.java
	java/sync/services/src/main/java/org/obm/sync/server/mailer/ErrorMailer.java
	java/sync/services/src/main/java/org/obm/sync/server/mailer/EventChangeMailer.java
	java/sync/services/src/test/java/fr/aliacom/obm/common/calendar/MailSendTest.java