Merge sequences of paths without attributes

===

<svg xmlns="http://www.w3.org/2000/svg">
    <path d="M 0,0 z"/>
    <path d="M 10,10 z"/>
    <path d="M 20,20 l 10,10 M 30,0 c 10,0 20,10 20,20"/>
    <path d="M 30,30 z"/>
    <path d="M 30,30 z" fill="#f00"/>
    <path d="M 40,40 z"/>
    <path d="m 50,50 0,10 20,30 40,0"/>
</svg>

@@@

<svg xmlns="http://www.w3.org/2000/svg">
    <path d="M0 0zM10 10zM20 20l10 10M30 0c10 0 20 10 20 20M30 30z"/>
    <path d="M 30,30 z" fill="#f00"/>
    <path d="M40 40zM50 50l0 10 20 30 40 0"/>
</svg>