#125 WR can't parse properly definition lists

[cilia gdd]

WikiRenderer fails to parse a definition list when its definition contains a colon (':').
For instance :

;term : my definition for this term is : CQFD.

//becomes

<dl>
<dt>term : my definition for this term is</dt>
<dd>CQFD</dd>
</dl>

If the definition contains multiples colons, it will truncate at the last colon position.

Tested with Plume v1.2.2 and the microcms.