travis: Build with Oracle JDK 8
travis: Use trusty for Ice 3.5
travis: Don't install python-* from trusty

It causes apt-get errors in the absence of a full dist-upgrade
(which isn't possible)
travis: Build python for one jdk only
adding email sender to Ice interface Admin.ice
renaming properties omero.resetpassword* to omero.mail.*
changing MailSender to JavaMailSender interface to supports MIME messages
moving to mail package and changing input args
testing SendEmail
sending email iterate recipients in steps
fixing spelling mistake
better handling input params
adding active users only flag
error handling
adding timouts to MailSender bean
adding cc and bcc
adding reset password functionality
adding test for reset password
moving prepareEmail to common resources
adding ome.services.util.MailUtil as a shared resources for sending email