Rework mail delivery

ATM we have mail sent via aspect which has the following implications:

• YeS must have sendmail capabilities
• Mail is lost if the server goes down

We need to rework this so that mail object is persisted to DB and then have cron in YUM that sends mail if there are any records in the mail table.
This will:

• Speed up checkout and registration process
• Remove dependency of YeS nodes on sendmail
• Allows to keep mail persistent until it is sent

Note: We can fully generate the mail message and store it in CLOB in DB together with recipient and sender address. Cron job will be a plain mail send - no template processing. We should also apply the same process to emails send from YUM.