master
build: tidy up and dedupe `strdup` functions
tests: always make bundles, adapt build and tests
cmake: rename `testbins` target to `tt`, restore internal option
autotools: limit checksrc target to ignore non-repo test sources
tests/server: drop unused `curlx/version_win32.c`
DoH: improvements
servers: drop duplicate (and interacting) ctrl handlers on Windows, add exit message
dnsd: add support for DoH
tidy-up: miscellaneous
servers: de-duplicate shutdown signal/logging code
servers: sync socket type global variables
tests/server/tftpd: replace duplicate code with `open_udp_sock()` call
servers: add option to build without window handler (Windows)