Use Velocity to generate email

https://github.com/zanata/zanata-server/pull/534

Squashed commit of the following:

commit cd0fbee650b4e92b9ccd795a9410259e87d8d2ca
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Tue Jul 22 14:14:35 2014 +1000

    Update unit test: HTML should appear after text

commit 58f956aa565815b47655213441f02df76a0070a9
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Fri Jul 18 18:10:50 2014 +1000

    Add @AutoCreate to injected components

commit d035448add298583965b7bb2abf87f6d94147427
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Fri Jul 18 18:08:27 2014 +1000

    Construct Reply-To correctly

commit 8ee323c2b561b415b8898e5e8a04457adecb90db
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Fri Jul 18 17:58:24 2014 +1000

    Add HTML mail part after text; produce text version of the HTML body

commit bae62c5a5f417600bc2bd0718f34649caceb0762
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Mon Jul 14 17:13:36 2014 +1000

    Refactor email-handling code and fix injection of mailSession

    Eliminate redundant template "email_activation.vm".
    Rename EmailUtil -> Addresses and use it more.
    Rename EmailBuilderStrategy -> EmailStrategy.
    Move all EmailStrategy classes to top-level under org.zanata.email.
    Ensure that all emails go through EmailService and get FacesMessages
       from Msgs so that they can be localised.

commit 8365f539ea292770257821f2953785c268199365
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Mon Jul 14 12:22:28 2014 +1000

    Make EmailBuilder into a component

commit 6f9ec47af5e5227fb3a68962ea97e34f54063b73
Author: Sean Flanigan <sflaniga@redhat.com>
Date:   Fri Jul 11 12:46:36 2014 +1000

    Use Velocity to generate email