This was based on libraries that were never ported to python3. If this
is still needed, it would have to be reimplemented with other newer
technologies.

This reverts commit 64950c5c0c5debb796bbf182d5b104c40853f3da.

This reverts commit 6135f41f49092270bdaff614bbd25aa7c0c62a41.

some conversion (TextDocument) depend on the content type, so it's
necessary to first update the content type before trying to convert to
base format