* add more documentation for properties
* fixes after a bit of trial-and-error with go-swagger
* fix email filter marshalling when there are no search criteria
* introduce an apidoc.yml that contains Swagger data and is merged when
generating the swagger.yml from sources
* ensure that all the jmap responses contain the SessionState
* implement missing errors that were marked as TODO
* moved common functions from pkg/jmap and pkg/services/groupware to
pkg/log and pkg/structs to commonalize them across both source trees
* implement error handling for SetError occurences
* Email: replace anonymous map[string]bool for mailbox rights with a
MailboxRights struct, as the keys are well-defined, which allows for
properly documenting them
* introduce ObjectType as an "enum"
* fix JSON marshalling and unmarshalling of EmailBodyStructure
* move the swagger documentation structs from groupware_api.go to
groupware_docs.go
* fix: change verb for /groupware/accounts/*/vacation from POST to PUT
* refactor the jmap package to split it into several files as the
jmap.api.go file was becoming too unwieldy
* refactor the Groupware handler function response to be a Response
object, to be more future-proof and avoid adding more and more
return parameters while handling "no content" response as well
* more godoc for the JMAP model
* add Email creation, updating, deleting (Email/set,
EmailSubmission/set)
* add endpoints
- POST /accounts/{accountid}/messages
- PATCH|PUT /accounts/{accountid}/messages/{messageid}
- DELETE /accounts/{accountid}/messages/{messageid}
