A new context is now created by calling Context::new and therefore you
always have a valid context. This is much more in Rust style and will
allow a lot of furture simplifications on the context itself.
The FFI layer has not yet been adjusted in this commit and thus will
fail.
* 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
