Added new (yet unproven) blocking Read trait for a rngs#45

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therealprof merged 3 commits intorust-embedded:masterfrom

therealprof:features/rng

Mar 14, 2018

Commits on Feb 25, 2018

Added new (yet unproven) blocking Read trait for a rngs.
therealprof
committed

Commits on Mar 2, 2018

Mark trait itself also as unproven
therealprof
committed

Commits on Mar 10, 2018

Added explanation about error handling
therealprof
committed