Compact syntax for settings.xml

[o-sdn-o]

The following declarations should be equivalent

<block>
    <item>
        <param=value/>
    </item>
</block>

<block/item/param=value/>

It turns out that the following declarations are also equivalent

<block>
    <param>
        <nested=value>
            <block1=value1/>
            <block2>
                <attr=value2/>
            </block2>
        </nested>
    </param>
</block>

<block/param/nested=value block1=value1 block2/attr=value2 />

[o-sdn-o]

This syntax modification does more harm than good. It's easier to generate a configuration with a script than manually write it out with a cool syntax.

Closed in favor of #393.