Squashed commit of https://github.com/addthis/hydra/pull/13.

add ValueMap and ValueArray iteration

commit 32b324d59be1d0f4e67a4e57bb06ffdc0e36ad93
Author: Michael Spiegel <spiegel@addthis.com>
Date:   Thu Jan 23 15:31:40 2014 -0500

    Simplification of handling return value in DataKeySieve2.
    Handling byte and custom types by converting them to strings to
    maintain preexisting behavior.

commit e33e196a931bd99170207424b1d936f518ed30ef
Author: Michael Spiegel <spiegel@addthis.com>
Date:   Thu Jan 23 13:01:43 2014 -0500

    Replacing "import foo.*" with explicit imports.
    Hydra code style guidelines discourage "import foo.*" statements.
    Some automated static analysis tools do not work well with these statements.

commit c285f70c76f58b4ea31b27ef2cc42afe47d2b4ed
Author: Stewart Allen <stewart@clearspring.com>
Date:   Thu Jan 23 10:51:22 2014 -0500

    add ValueMap iteration