Reset is an internal value that received messages should not be able to set.
Also return an error on any value other than "mutual" and "nopreference", errors are converted to NoPreference by the caller.
if the past we had lots of crashes because of unexpected unwrap failures,
mostly related to string.
this commit avoids them eg. for string-conversions that may panic
eg. when encountering a null-byte or by logical programming errors
where an object is assumed to be set but is not under unexpected circumstances.
* refactor(contact): rename and rusty memory allocations
* refactor(contact): use enum to indidcate origin
* refactor(contact): safe blocking and unblocking api
* refactor(contact): only safe and no more cstrings
* refactor: safe sql access
* Clean up the worst rebase mistakes
* Some more progress on the rebase fallout and this branch
* upgrade and compile again
* cleanup from rebase
* example of how to prepare now
* rebase fixes
* add sql.query_map
* less preparation
* more improvements in sql code
* fix string truncation
* more prepare conversions
* most prep done
* fix tests
* fix ffi
* fix last prepares
* fix segfaults and some queries
* use r2d2 pool
* fix dc_job sql call, to reduce contention
* try newer rust
* No more vararg printing (drop dc_log_)
* ignore expected errors
* fix: uses exists instead of execute where needed
* fix: get_contacts logic was broken
* fix: contact creation
* test on 32bit linux
* ci: try running 32bit without cross
* undo 32bit tests
* refactor: rename dc_sqlite3 to sql
* fix: safer string conversions
* more string fixes
* try fixing appveyor build to 64bit
* chore(ci): hardcode target
* chore(ci): appveyor
* some cleanup work
* try fix darwin
* fix and improve sql escaping
* fix various bugs
* fix chat deletion
* refactor: cleanup config values and move to their own file
* refactor: move more methods onto the sql struct
* dont panic on failed state loading
* first round of cr
* one more cr fix
* stop using strange defaults
* remove unused escapes
