Allow classes to be namespaced with subdirectories

Classes files may now reside in subdirectories, which act as namespaces.
For instance, a class ``ssh.server`` will result in the class definition
to be read from ``ssh/server.yml``. Specifying just ``ssh`` will cause
the class data to be read from ``ssh/init.yml`` or ``ssh.yml``. Note,
however, that only one of those two may be present.

Signed-off-by: martin f. krafft <madduck@madduck.net>
diff --git a/doc/source/changelog.rst b/doc/source/changelog.rst
index a0ab3db..25bda17 100644
--- a/doc/source/changelog.rst
+++ b/doc/source/changelog.rst
@@ -5,6 +5,8 @@
 ========= ========== ========================================================
 Version   Date       Changes
 ========= ========== ========================================================
+                     * yaml_fs: classes may be defined in subdirectories
+                       (closes: #12, #19, #20)
                      * Migrate Salt adapter to new core API (closes: #18)
                      * Fix --nodeinfo invocation in docs (closes: #21)
 1.2.2     2013-12-27 * Recurse classes obtained from class mappings