This implements a simpler version of the wlroots logger for swaylock.
With this logger, the dependency on wlroots can be dropped. This also
adds a debug flag and disables debugging output by default
Today I learned that GNU flaunts the POSIX standard in yet another
creative way. Additionally, this adds some security improvements,
namely:
- Zeroing out password buffers in the privileged child process
- setuid/setgid after reading /etc/shadow
This involves setuid'ing swaylock, which then forks and drops perms on
the parent process. The child process remains root and listens on a pipe
for requests to validate passwords against /etc/shadow.
