Update Persistor to use new utils so that it supports mongo types

Signed-off-by: John Oliver <johno@insightfullogic.com>
Merge branch 'master' of https://github.com/vert-x/mod-mongo-persistor into mongo-types

Signed-off-by: John Oliver <johno@insightfullogic.com>

Conflicts:
	README.md
Rename tests and tidy up as per pull-request review.

Signed-off-by: John Oliver <johno@insightfullogic.com>
Merge pull request #71 from johnoliver/mongo-types

Update Persistor to use new utils so that it supports mongo types