samba4: new package

Samba 4.1.x uses the waf build system which isn't very cross-compile
friendly, and also some tests are formulated in a way that isn't
cross-build friendly either by needing to run them.

For this reason the samba4 build system includes a way to define
answers for many of the tests, but this support isn't complete
and some tests still want to be executed.

Samba 4.1.x also requires a proper answers file for each architecture,
and at the moment i've only tested for ARM and PowerPC so only those
architectures are supported to begin with. To add support for another
architecture basically copy one of the cache files to the proper name,
enable it in Config.in and adjust endianess and all of the "size of"
answers. I'm in the process of automating the sizeof and endianess
answers within the samba build system to make them cross friendly
to simplify the answers file to just one generic linux variant.
The 3.6.x branch is still security supported for the forseeable future.

I'm currently working with samba upstream to solve many of these
issues but this will probably happen with the yet unreleased
4.2 branch only.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>