* cygwin.din (clock_nanosleep): Export.

* posix.sgml (std-notimpl): Move clock_nanosleep from here...
(std-susv4): ... to here.
(std-notes): Note limitations of clock_nanosleep.
* signal.cc (clock_nanosleep): Renamed from nanosleep, adding clock_id
and flags arguments and changing return values throughout.
Improve checks for illegal rqtp values.  Add support for
CLOCK_MONOTONIC and TIMER_ABSTIME.
(nanosleep): Rewrite in terms of clock_nanosleep.
(sleep): Ditto.
(usleep): Ditto.
* thread.cc: Mark clock_nanosleep in list of cancellation points.
* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.

winsup/cygwin/thread.cc

@@ -577,7 +577,7 @@ pthread::cancel ()
 
     * accept ()
     o aio_suspend ()
-    o clock_nanosleep ()
+    * clock_nanosleep ()
     * close ()
     * connect ()
     * creat ()