TranslatePress fetches regular language

[sybrew]

From Vladimir's findings:

Descriptions and titles aren't translated with TranslatePress.

TranslatePress uses output buffering to translate the page instead of assigning a new ID to the page.
This makes the Core APIs of WordPress send default, untranslated content.

We could use trp_translate to translate the content of select fields (with all performance implications attached), but it could add HTML.
So, in our content fetchers (like tsf()->fetch_excerpt()), which expect raw HTML, we should add a filter to allow this type of translation.