v1.0-rc1

• Modify docs for v1.0-rc1 release
• make extensions follow the same pattern as normal attrs - #505
• remove proto - see issue 504
• Syntax fixes - #506
• Update AVRO mappings to match current event schema and type system. - #497
• Fix up JSON type mappings - #496
• Extensions are not allowed to be nested any more.
• Only OPTIONAL attributes (conditional not needed
• Clarifications on the HTTP transport binding - #488
• remove dataencoding and intro data_base64 in JSON - #492
• Cleanup: Map and add URI in formats; re-add "Type System" heading - #493
• Remove "printable", disallow dodgy Unicode
• Tweak URI-references and be smart with Strings - #478
• tweak how we talk about data
• Allow for a LOA w.r.t. voting rights
• s/schemaurl/dataschema/ to be consistent - #475
• add ptr to sdk doc
• Add section to primer about error handling
• Avro Event Format for CloudEvents - #463
• We no longer put extensions into an 'extensions' bag
• Change wording to make it clear that Any which doesn't result in Map is allowed.
• Address Persistence
• Merge changes to spec.md
• Update with suggestions from PR=
• Kafka transport binding v2 - #337
• Clarifications on batching to address - #414
• minor github tweaks
• Fix some typos and grammatical errors per MS Word
• add s3
• Add a spot to describe adapters
• Forwarding OPTIONAL attributes - #461
• Fix capitalization of MAY NOT/SHOULD
• Make formatting of Any-context explicit in transports/formats.
• Add Any-context type.
• Merge remote-tracking branch 'upstream/master' into where-were-going-we-dont-need-maps
• Remove Map from allowed Context Attribute types
• Modify roadmap with a more clear goal of getting to v1.0
• Add non-goals for routing information.
• Primer edits - Architecture section - #390
• Add commercetools to contributors
• Added James Roper/Lightbend to contributors
• Fix README table - missing protobuf and reorder
• #436 Clarifying that Any can take the shape of any other type
• Add a little clarity around "type"
• v0.4-wip
• Be clearer about "time"