Second release candidate for version 1.0.0

Protobufkdb enhancements:

• Message representation
  Previously protobufkdb represented a proto message in kdb as a mixed lists of field values in field positional order. This is for performance reasons and to more closely tie in with how protobuf serializes messages.
  However, some users may prefer messages to use a dictionary from symbol field names to a mixed list of field values, more similar to how JSON is represented. In this case each field is be looked up by its name so the positional order is no longer required.
  Both styles are now supported by separate APIs.
• Type mapping updates
  Proto string fields are mapped to kdb+ char lists
  Proto bytes fields are mapped to kdb+ as byte lists
  Proto map-key string fields are mapped to kdb+ symbols
• Bugfixes
  Messages where are fields have the same type can be serialized
  Dynamic import errors are cleared correctly