wayland: Bump RLIMIT_NOFILE limit
As a wayland compositor kwin can hold many open file descriptors and therefore it's easier for it to hit the soft file descriptor limit. This change makes kwin_wayland bump the soft file descriptor limit to the hard limit. With systemd, it's usually 500K.
In order to prevent causing mess in child processes, pthread_atfork() is used to register a handler which will be invoked in the child process after fork() in order to restore RLIMIT_NOFILE to its original value.
fixes #75 (closed)
Edited by Vlad Zahorodnii