Update to 0.9.12 (#949286)
    
    This update incorporates two packages that were distributed separatately
    before: zeitgeist-datahub and libzeitgeist.
    
    The latter has also gone through some API changes, and the library name
    has changed from the standalone libzeitgeist-1.0 to libzeitgeist-2.0.
    This ensures that the version bundled with zeitgeist and the separately
    packaged libzeitgeist are parallel installable, making it possible to
    keep the standalone libzeitgeist package around until all users have
    been ported over.
    
    The separate zeitgeist-datahub however needs to be retired.
    
    (F19+ only, please don't cherry-pick it to earlier releases.)