* plugins.d/splashy.c (main): Bug fix: really check return value from "sigaddset". Fix some warnings on 64-bit systems.
* plugins.d/usplash.c (termination_handler, main): Save received signal and re-raise it on exit. (usplash_write): Do not close FIFO, instead, take an additional file descriptor pointer to it and open only when needed (all callers changed). Abort immediately on EINTR. Bug fix: Add NUL byte on single-word commands. Ignore "interrupted_by_signal". (makeprompt, find_usplash): New; broken out from "main()". (find_usplash): Bug fix: close /proc/<pid>/cmdline FD on error. (main): Reorganized to jump to a new "failure" label on any error. Bug fix: check return values from sigaddset. New variable "usplash_accessed" to flag if usplash(8) needs to be killed and restarted. Removed the "an_error_occured" variable.