Implemented DumpUnmarshaller to unmarshal individual pages and revisions for export format 0.5, 0.6, 0.7 and 0.8

* sweble-wikitext 12bad4f...cc2118e (2):

    commit cc2118e94216f07778c14d7cf756d24e45db666a

        Implemented DumpUnmarshaller to unmarshal individual pages and revisions for export format 0.5, 0.6, 0.7 and 0.8

    commit b0d2e91d7428e92ac0ac5353ee36aab58f98039c

        Made it possible to unmarshal single page using swc-dumpreader