Dictionary implements IDictionary and IDictionary<TKey, TValue>

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extra : source : 666e9778ab47cc7414d8f7ec00edb73be113beb6
Test added, problems fixed for Dictionary interface implementation.

--HG--
extra : amend_source : 3632e24194f8836ca4bd3a16c72f3613ce84475f
Merge pull request #439 from iskiselev/IDictionary

Dictionary implements IDictionary and IDictionary<TKey, TValue>