Add MessageSerializer into the mix.

  Closes #22

Squashed commit of the following:

commit 6b05414442e5e45ae68d12e7423ed3f76fc243fd
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 17:26:17 2014 -0400

    Use G++-4.7

    Use vanilla GCC.

    Remove old g++.

    Make sure build-essential is there.

commit cb4abd934361ab573b6f966d9236b9be799fef1f
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 17:26:17 2014 -0400

    Use G++-4.7

commit 556a187778981d0cfba82bf8b800ced1bb3565ec
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 17:24:01 2014 -0400

    Use new toolchain for G++ 4.7

commit 138e5dcc432812529ad0de7364bbaa37b26d35ed
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 17:19:16 2014 -0400

    Light formatting.

commit 05457d4b8a4d2bebd22131a5fce2fc52ae638f32
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 17:14:30 2014 -0400

    Improved setters for message and used asserts.

commit d6394a786dc65e51e79fab032651d580e3bbb971
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 16:58:50 2014 -0400

     #22 - Updated Message class and added more tests to ensure valid changes.

commit 4651ca7e352dd82ae79a5cbc382104f6857120b8
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 16:51:33 2014 -0400

    Added missing methods to Message.

commit 4e4f264df081a865d8aad79afbfab292f6e80967
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 16:27:50 2014 -0400

     #12 - Add logic to import the payload from JSON.

commit 2a7428d1d8ad339c7ed902616fb650ec4cc04517
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 15:56:04 2014 -0400

    Added 'jsoncpp' to the test suite.

commit fb146b798e77515ffeaa781fe71744d382e7eccc
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 15:53:27 2014 -0400

     #12 - Updated serializer to use jsoncpp.

commit 0a0f69441d53a71556a6957ac3bb2a4b8ee4482d
Author: Jacky Alciné <me@jalcine.me>
Date:   Sat Jul 19 14:51:44 2014 -0400

     #22 - Added `MessageSerializer` and accompanying tests.