Build VirtualBox modules 4.2.16

- Older versions do not build on 3.8.
- Rewrite the multi-kernel build to be more clean.
- Get rid of the last packages in /usr/share/amnesia/packages/.
Improve comment
Fix link. Thanks to irregulator@riseup.net for the patch.
updated PO files
Add meta title.
Add pt-br translation for tails 1.0 release.
Update pt-br translation of front pages.
Add back a first level header to point to installation instructions
Make the explanation of ISO image a bit more visible
Adding problematic laptop
updated PO files
Fix language
updated PO files
Add UEFI test results for VirtualBox.
Add another Vagrant compatibility wrapper.
Fix buggy memory checks for RAM building.

We have to take into account which state the Vagrant VM is in for
determining *where* we check if enough memory is available for a RAM
build. If it's off, we check the host; if it's on we check the
VM. Previously we always checked the host, which doesn't make sense
when the VM is already started.
De-bump memory for disk builds.
Simplify build script.

We are already checking if enough memory is available in the Rake
file, so we might just as well allocate all memory for the tmpfs. This
de-duplicates the information now provided in BUILD_SPACE_REQUIREMENT
as well.
Insist on the fact that the persistence is encrypted
(doc) removed gpgapplet outdated paragraph