As we are using CSL (Citation-Style Language) to store and display works, we should also support styled text in titles using the CSL approach: http://citationstyles.org/downloads/upgrade-notes.html#rich-text-markup-within-fields
<sc> is obviously not a proper HTML tag, and should be displayed as <span style="font-variant: small-caps;">Text</span>.
<span style="font-variant: small-caps;">Text</span>
To implement this we need to:
use title_display in plos import to preserve formatting. #225
keep tags allowed in CSL when sanitizing titles. #225
Display work titles as HTML. Closes #225.