Instead of adding stuff to `_shutdown()`, we can now register a shutdown
routine from the respective `init()` function of our modules.
This also has the advantage, that we're sure they're called in reverse
order from how the initialization happened.
I didn't simply use `atexit()` because POSIX says that the number of
possible callbacks is limited (min 32) and I was not sure whether
we will maybe extend this number at one point.
Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>
98c38dc6d6
sets C99 as standard.
strdup() is not part of C99.
For now set `-D_POSIX_C_SOURCE=200809L` macro to have strdup() in C99.
Using `gnu99` instead would be another option.
We should take more care to use glib functions whenever possible.
Regards https://github.com/profanity-im/profanity/issues/1357
