Squashed commit of the following:

commit 35eaf60b88e4d521a66a1e295eae4e4a97bd1611
Author: Alexis Mineaud <alexis.mineaud@gmail.com>
Date:   Fri Feb 14 00:46:25 2014 +0100

    Set thread as unread when creating a new thread, add TODO.

commit 6dcfd262c75616847a55af07879b8246ff6826f6
Author: Alexis Mineaud <alexis.mineaud@gmail.com>
Date:   Fri Feb 14 00:29:18 2014 +0100

    Fix tags add/remove.

commit 74faea4f7aba1c56073eb9212c87b001c317f5e2
Author: Alexis Mineaud <alexis@gandi.net>
Date:   Thu Feb 13 18:31:49 2014 +0100

    Continue tags implementation.

commit b999e4aa3821e6d6c2b4a34e5407579df3b587ea
Author: Alexis Mineaud <alexis.mineaud@gmail.com>
Date:   Thu Feb 13 01:26:48 2014 +0100

    Trying to post labels...