Deltachat

- 1056 avoid panicking when we couldn't read imap-server's greeting
message

- 1055 avoid panicking when we don't have a selected folder

- 1052 1049 1051 improve logging to add thread-id/name and
file/lineno to each info/warn message.

- 1050 allow python bindings to initialize Account with "os_name".

- 1044 implement avatar recoding to 192x192 in core to keep file sizes small.

- 1024 fix 1021 SQL/injection malformed Chat-Group-Name breakage

- 1036 fix smtp crash by pulling in a fixed async-smtp

- 1039 fix read-receipts appearing as normal messages when you change
MDN settings

- 1040 do not panic on SystemTimeDifference

- 1043 avoid potential crashes in malformed From/Chat-Disposition... headers

- 1045 1041 1038 1035 1034 1029 1025 various cleanups and doc
improvements

- alleviate login problems with providers which only
support RSA1024 keys by switching back from Rustls
to native-tls, by using the new async-email/async-native-tls
crate from dignifiedquire. thanks link2xt.

- introduce per-contact profile images to send out
own profile image heuristically, and fix sending
out of profile images in "in-prepare" groups.
this also extends the Chat-spec that is maintained
in core to specify Chat-Group-Image and Chat-Group-Avatar
headers. thanks r10s and hpk42.

- fix merging of protected headers from the encrypted
to the unencrypted parts, now not happening recursively
anymore. thanks hpk and r10s

- fix/optimize autocrypt gossip headers to only get
sent when there are more than 2 people in a chat.
thanks link2xt

- fix displayname to use the authenticated name
when available (displayname as coming from contacts
themselves). thanks simon-laux

- introduce preliminary support for offline autoconfig
for nauta provider. thanks hpk42 r10s

- fix 994 attachment appeared doubled in chats (and where actually
downloaded after smtp-send). hpk42

- fix packaging issue with our rust-email fork, now we are tracking
master again there. hpk42

- fix 976 -- unicode-issues in display-name of email addresses. hpk42

- fix 985 group add/remove member bugs resulting in broken groups. hpk42

- fix hanging IMAP connections -- we now detect with a 15second timeout
if we cannot terminate the IDLE IMAP protocol. hpk42 link2xt

- fix incoming multipart/mixed containing html, to show up as
attachments again. Fixes usage for simplebot which sends html
files for users to interact with the bot. adbenitez hpk42

- refinements to internal autocrypt-handling code, do not send
prefer-encrypt=nopreference as it is the default if no attribute
is present. linkxt

- simplify, modularize and rustify several parts
of dc-core (general WIP). link2xt flub hpk42 r10s

- use async-email/async-smtp to handle SMTP connections, might
fix connection/reconnection issues. link2xt

- more tests and refinements for dealing with blobstorage flub hpk42

- use a dedicated build-server for CI testing of core PRs