+CosmosPruner, Log polishing, Fixed bad idleDelay

Added

• Cosmos: Add CosmosPruner #80
• Cosmos: Exposed optional maxEvents and maxBytes arguments for CosmosSink #84

Changed

• Cosmos: Tweak logging in CosmosSink #85
• Consistently exposed optional idleDelay and pumpInterval arguments for all Projectors and Ingesters #81

Fixed

• Kafka.StreamsProducerSink: Changed bad default idleDelay from 0ms to 1ms #82
• Corrected Cosmos + Stream Sink error logging #79

See ChangeLog

Targets Equinox.Cosmos 2.3.0, Equinox.EventStore 2.0.0, SqlStreamStore 1.2.0-beta.8, FsCodec 2.0.0, FsKafka 1.5.x