waitFor() does not allow intervals greater than 1 second on some platforms

Summary

waitFor() uses usleep(), which may be limited to a maximum of 1 second on some platforms.

Possible fixes

Create new methods waitFor(timespec) and waitFor(uint seconds, uint nanoseconds),

which use nanosleep instead.

Note that nanosleep has other advantages e.g. on linux but not on QNX compared to usleep.