added confirmation personal note to the sender signature

updated server data model and documentation

update package to use for mime

tiny test update

updated library version

small model update

clients can be retrieved with custom API url now

remove obsolete test

Added error code to error messages that have error code. Separated er…

…ror handling from http client handler. Added parameter usage to message details endpoint

added support for sending per message stream and inline attachment su…

…pport for templates