update xsl rule for moderncv personal position/title

[dginev]

A bit of a minor tweak that makes the moderncv.cls output capable of handling a simple plain-text position (originating in the \title macro). The previous version was expecting a multiline construct in a \vbox, which is a bit too specific.

Funny story how I stumbled on it...

[dginev]

Also, this could be refactored to a dedicated rule specific to ltx:contact[@role='position'], let me know if that's preferable to the xsl:if test.

[brucemiller]

seems reasonable, although there may be a more general approach (later).