#6 Add ability to verify uniqueness

[Bors]

Add uniqueness for both dictionary and invert. Request
could be like:

<entry1><entry2>...<entryN>

Response could be non joined invert list for every
entry.

<entry_list1><entry_list2>...<entry_listN>

It will allow to build intersected list on the node.
If some row contain even one entry in the intersected
result list it will be rejected.