Remove meaningless strlcpy result comparison

The test of strlcpy's return value was meaningless, and resulted in a
compile warning from clang.
Consistent daemonized pid, symlink relative path handling

When daemonizing, change to the root directory before creating the pid
file and pty symlinks in order to allow cleanup of relative files and
links, without holding open the original working directory.
Unfortunately this requires full path names for files and links when
using the -d option.
Handle relative pid file, symlink names when daemonizing

Updates the program's cleanup code so that it attempts to restore the
original working directory when shutting down, so that relative pid
file and pty symlink path names can work with daemonization enabled.

closes #13