Move IMTProtoConnection to separate file.
Update MTProto schema and packages.
Fixed incorrect assertions.
Solution reorganization. Added Shared project.
Updated packages.
Added MTProtoBuilder.
Updated R# team-shared settings.
Cleanup.
Refactored MTProtoBuilder.
Updated R# team-shared settings.
Added BuildAuthKeyNegotiator to MTProtoBuilder.

Due to refactoring related to MTProtoBuilder were removed:
TransportConfigProvider, MTProtoConnectionFactory.
Renamed TransportConfig to ITransportConfig.
Extracted IAuthKeyNegotiator <- AuthKeyNegotiator.
Updated build scipts.
Added auto-generated MTPRoto schema methods impl.
Clean-up.
Updated SharpMTProto schema.
Added HashServices for PCL.
Clean-up BadMsgNotificationHandler.
Updated version to 0.5.0. Updated README.